neuronstagingarea.js: fix automatic color assignment.

Colors could be repeated if a skeleton was removed and then another added.
Neuronstagingarea.js: remove unused function.
connectivity: fix incorrect function name.
neuronstagingarea.js: fix removal of skeletons from Selection Table.

The cached array indices were not updated correctly.
neuronstagingarea.js: rename local variable to avoid confusion with member variable.
webglapp.js: Fix asynchronous issue

When loading a skeleton into the 3d view, this takes some time,
and during this time the skeleton may have been removed from the selection,
and therefore upon receiving the json with the skeleton data, this must
be ignored.
Merge branch 'master' of github.com:acardona/CATMAID
neuronstagingarea.js: simplify a statement.
neuronstagingarea.js: fix GUI readout.
neuronstagingarea.js: fix error when removing a single skeleton

Turns out that, in javascript, Array.splice(undefined, 1) removes
the first element of an array instead of raising an error.
webglapp.js: user-friendly handling of error when a skeleton is missing
and therefore cannot be loaded.

Don't stop loading the others, and offer to remove the missing ones
from the Selection Table.
webglapp.js: fix the YZ to ZY (that's what it is) and add ZX view.

Also make the dorsal and lateral views from afar, so that the whole
box is visible.
webglapp: destroyable mouse controls that don't retain a context
that would capture elements of the 3d view like Space etc.
neuronstagingarea: prevent error when closing it if the 3d view is not open.
webglapp: destroyable mouse controls that don't retain a context
that would capture elements of the 3d view like Space etc.
neuronstagingarea: prevent error when closing it if the 3d view is not open.
webglapp.js and neuronstagingarea.js now "use strict";
webglapp.js: dispose of geometries and materials when done with them.

The 3d widget had never done that, surprisingly.

Additionally, now all Skeleton instances reuse the connector materials,
given that their color never changes.
neuronstagingarea.js: fix inability to remove first element of the selection.

Turns out that zero is falsy in javascript.
Merge branch 'master' of github.com:acardona/CATMAID

Conflicts:
	django/applications/catmaid/static/webglapp.js