wbo is now more observable

When using an iPad with an apple stylus, finger touches now trigger the whiteout tool.
This behavior can be disabled by setting the environment variable AUTO_FINGER_WHITEOUT=disabled

* Auto white-out with a finger when using stylus

* Add AUTO_FINGER_WHITEOUT config variable

* Use local variable to remember if stylus was used and make behavior configurable

* Delete "stylus" property

* Make AUTO_FINGER_WHITEOUT on by default

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

* Delete parseBool, add note about iPad/Pencil

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

* add option to block tools

* use tool name instead of computing an id

Co-authored-by: Ophir LOJKINE <ophir.lojkine@auto-grid.com>

* require comma separated list as input of blocked tools environment variable

Co-authored-by: Ophir LOJKINE <ophir.lojkine@auto-grid.com>

* Log attempts to use blocked tools

Co-authored-by: Ophir LOJKINE <ophir.lojkine@auto-grid.com>

* fix syntax

* require tool names to not have a comma in them

* Update server/configuration.js

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

* Added cursors

* Prepare cursor code for future settings to toggle cursors on or off.
Let cursor be the color the person has currently selected

* fix cursor on mobile (still won't display it in most cases as there is no hover on mobile but at least it won't throw errors)

* use correct size for cursor

* throttle cursor update rate to dramatically improve performance by eliminating congestion

* fix remote cursor size on desktop

* show own cursor by default and renove offset

* use svg as mouse cursor for pencil to be able to apply a reduced opacity to it and view our cursor

* don't throttle local cursor

* throttle local cursor at an independent higher rate. This could be made user adjustable for low power devices

* remove let and const from client-side code

* get emit count and emit count period from configuration

* reduce network cursor updates a lot to prevent instantly getting banned with the current defaults

* prevent eraser from deleting cursors

* use group inside of svg as drawing area and only delete elements inside it with the eraser

* use transform: translate to move cursors around instead of manipulating x and y directly

* fix: add socket ids to cursor messages

* fix incorrect remote cursor scaling and make local cursor visible again after it has been moved after being hidden due to inactivity

* create cursors in a proper fashion and keep them in a separate group

* scaling has been fixed in a1a5580

* move duplicated cursor creation code to function

* show cursors above content

* pass some of ther server configuration through to the client

* fix bug introduced in a833ce9

* allocate at most half of the allowed traffic to cursor updates

* remove debugging leftover

* use feature detection instead of ua sniffing

Co-Authored-By: Ophir LOJKINE <ophir.lojkine@auto-grid.com>

* fix regression where local cursor color was not updated on color change

* Define the cursor as a tool

* Remove the cursor tool from the UI

* Throttle remote cursor updates, not local ones

* Do not increment notification count on cursor move

* Use only one pencil icon

Use the same image for the pencil icon in the menu
and the pencil cursor that appears while drawing

* Add a test for the new cursor feature

* only stop drawing remote cursor when using some tools and always draw local cursor

* increase idle period before hiding cursor

* change idle duration back and set whether a cursor should be sent when using a tool in the respective tool

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

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

Thanks @iblech

Fixes #34