Bump supported Firefox to 4

Range.getBoundingClientRect is not supported in FF 3.x
[sass mode] Clean up coding style
[sass mode] Terminate multiline comments on dedentation

Closes #2752
[sass mode] Add support for indented single-line comments

Issue #2752
[merge addon] Add a revertButtons option to turn off revert buttons

Closes #2754
[slim mode] Add
[slim mode] Integrate

Issue #2755
Add mimetype text/x-nesc
[merge] new allowEditingOriginals option to edit all compared files
[verilog mode] Addressed indentation issue

Blocking indentation for import/export keywords
[php mode] Add json, curl, mysqli extensions
[sql-hint addon] Clean up, fix handling of whitespace

Closes #2761
[sql-hint addon] Properly complete on dot tokens
Include rtl and ltr marks as special chars, don't render them

Issue #2759
[real-world uses] Add Phantomus and Wamer
[vim] visual block bugs