Update Resources/Help/Documentation/working_with_textures.html

Copy/Pasted the text from kduske into here because I can't figure out Git. o.o
Update Resources/Help/Documentation/working_with_textures.html

Added in missing section re: mouse shortcuts.  Changed keyboard shortcut title to fit mouse shortcut section title.
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Documetation Update
Merge remote-tracking branch 'upstream/master'
Documentation Update: Finished original sections of shaping_brushes and added images.  Need to finish section on multiple brushes in selection + vertex editing
Merge branch 'master' of https://github.com/necros0/TrenchBroom
Fix some problems with the cascaded entity popup menus.