* Allow parentheses in board names

* Pass over the string only once while escaping html special chars (#82)

Co-authored-by: Paolo Bolzoni <paolo@cagla.jp>

* Add a spanish translation

Thanks to @beccobunsen

See #94

* add an italian translation

Improve the spanish translation and

* Added "free online whiteboard" to the main title

* add translations for grid

* Fix translations for "white-out" in es and it

Co-authored-by: Paolo Bolzoni <paolo.bolzoni1@studenti.unipr.it>
Co-authored-by: Paolo Bolzoni <paolo@cagla.jp>

* make live version render single-point paths the same as preview does

* implemented smoothing in server side rendering

* separate preview from export

* ensure correct handling of paths with only one child

* break out rendering of 3rd point and up into separate function

* changed test for 2 points to math current implementation and added a test for a bezier curve with 3 lines

* deduplicate code to extrapolate points for bezier curves

* fix merge

* Factor more code between the client and the server

Completely remove the straight line approximation foor paths

Vastly improve preview performance

* Add support for opacity in preview

* Stream board previews to the browser

Previously, svg board previews were generated in memory
and then pushed to the client.

They are now streamed to the client without blocking the main thread.

# Performance

## Before

$ ab -n 30 -c 15 http://localhost:8080/preview/ic3
This is ApacheBench, Version 2.3 <$Revision: 1843412 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient).....done

Server Software:
Server Hostname:        localhost
Server Port:            8080

Document Path:          /preview/ic3
Document Length:        14352691 bytes

Concurrency Level:      15
Time taken for tests:   19.499 seconds
Complete requests:      30
Failed requests:        0
Total transferred:      430588920 bytes
HTML transferred:       430580730 bytes
Requests per second:    1.54 [#/sec] (mean)
Time per request:       9749.374 [ms] (mean)
Time per request:       649.958 [ms] (mean, across all concurrent requests)
Transfer rate:          21565.33 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.1      0       0
Processing:   727 8885 1561.6   9220    9817
Waiting:      718 5380 2668.8   5569    9549
Total:        727 8885 1561.6   9220    9817

Percentage of the requests served within a certain time (ms)
  50%   9220
  66%   9239
  75%   9245
  80%   9248
  90%   9560
  95%   9811
  98%   9817
  99%   9817
 100%   9817 (longest request)

## After

$ ab -n 30 -c 15 http://localhost:8080/preview/ic3
This is ApacheBench, Version 2.3 <$Revision: 1843412 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient).....done

Server Software:
Server Hostname:        localhost
Server Port:            8080

Document Path:          /preview/ic3
Document Length:        14352687 bytes

Concurrency Level:      15
Time taken for tests:   17.647 seconds
Complete requests:      30
Failed requests:        0
Total transferred:      430588020 bytes
HTML transferred:       430580610 bytes
Requests per second:    1.70 [#/sec] (mean)
Time per request:       8823.254 [ms] (mean)
Time per request:       588.217 [ms] (mean, across all concurrent requests)
Transfer rate:          23828.86 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.1      0       0
Processing:   719 8212 1440.6   8657    8810
Waiting:      701 4666 2324.8   4788    8769
Total:        719 8212 1440.6   8657    8811

Percentage of the requests served within a certain time (ms)
  50%   8657
  66%   8670
  75%   8691
  80%   8790
  90%   8802
  95%   8808
  98%   8811
  99%   8811
 100%   8811 (longest request)

* Write the element id and opacity only when needed

* Fix a bug in wbo_pencil_point

* Rework the integration tests for the pencil tool

* Test server-side rendering in integration tests

* Remove unused function

* Remove unused id fallback

* set return types

* fix rectangle

* set fill for rect in stylesheet instead

Co-authored-by: Ophir LOJKINE <pere.jobs@gmail.com>

  - use promises instead of callbacks
  - avoid polluting stderr, and instead log rendering time in the standard log format
 - cache rendered boards for only 30 seconds

* Added Circle tool as alternative function of Rectangle tool

* change toggle function to work with new icon structure and toggle name

* split circle into separate tool and added ellipse as secondary function. Also added server side rendering for svg export

* change ellipse to be default

* change circle behaviour to same as inkscape

* toggle to alternative while holding shift

* append to drawing area instead of svg root

* don't update shape after it has been drawn

* Stop logging all rectangles

* Remove es6

* Remove more es6

* Fix a few bugs with circle to ellipse toggling

* Calculate the circle params at creation time, not at rendering time

* Make the behavior of the shift key consistent

When shift is pressed, the current function is reversed: the circle tool draws an ellipse and the ellipse tool draws a circle.
This makes the tool easier to grasp.

* Add required translations

* german translation

* Update the shape immediately when pressing shift

* Fix server-side ellipse rendering

* Add a test for the circle tool

Co-authored-by: Robert Beach <rdbeach@gmail.com>
Co-authored-by: Ophir LOJKINE <pere.jobs@gmail.com>

There are now several different configuration
variables through which WBO can be configured.

Thanks @iblech

Fixes #34