do not build VFS for excluded directories
remove unneeded read actions
TemplateState: yet another debug info
(cherry picked from commit c33e62c)
[r=peter]
Add toString method in diagnostic purposes
(cherry picked from commit c351f3b)
[r=cdr]
WEB-11445 AngularJS filters break Emmet

 - delete key and commit document after key processing
(cherry picked from commit e30e9a7)

[r=ushakov]
TemplateState: yet another debug info
(cherry picked from commit 6a86074)

[r=peter]
extract BasicGutterContentProvider — we need gutter content provider in any case to provide pretty UI (in/out markers)
(cherry picked from commit ea9d3c6)