Initial implementation search exclusion using project-based view setting.
Remove an incorrect assignment.
Switch to global view state instead of project-based one and also limit it to ten globs.
Fix JSLint error for extra trailing whitespaces.
Merge remote-tracking branch 'origin' into rlim/search-exclusions
First pass at UI for Find in Files exclusion filters. Not wired up to
seach implementation or prefs yet.

Changes the search bar to use ModalBar's autoClose behavior; no longer
assumes its code is the only thing to ever close the bar. Adds a new API to
ModalBar to allow the search bar to be 'locked open' when it would normally
close, as Find in Files needs for its no-results state and when the filter
editor dialog is open.
Merge remote-tracking branch 'origin/rlim/search-exclusions' into pflynn/search-exclusions

* origin/rlim/search-exclusions:
  Fix JSLint error for extra trailing whitespaces.
  Switch to global view state instead of project-based one and also limit it to ten globs.
  Remove an incorrect assignment.
  Initial implementation search exclusion using project-based view setting.
Wire up file exclusion UI to Find in Files search code & preferences.
Centralize code in FileFilters module. Switch prefs from single set of at
most 10 globs to an MRU list of at most 10 separate filters, each of which
is an unlimited set of globs. Properly update dropdown UI when editing
dialog is dismissed
use styleSheetAdded and styleSheetRemoved to replace deleted getAllStylesheets API
fix related doc ref count errors
Hoist out a generic DropdownButton widget from CSSInlineEditor, and use it
in FileFiters picker UI also, replacing the <select> element it used before.

Further enhance ModalBar to accept focus going to popup elements outside
its DOM hierarchy if they point back to the ModalBar as the popup's opener.
fallback to getAllStyleSheets if available
add error handling when getAllStyleSheets is not found in inspector protocol
do not change live dev status for inspector errors
File exclusions usability improvements:
- Automatically add ** prefix and/or suffix in most cases
- Link to real docs page on wiki
- Show full filter set in picker button's tooltip
Fix bug that snuck into last FileFilters commit at last minute.
Small starter set of unit tests for FileFilters auto-prefix/suffix behavior.

Also fix whitespace JSLint glitch in unrelated unit-test file.
account for styleSheetId changes after a CSSDocument reloads
remove styleSheetRemoved handler. handle weird chrome behavior where interim updates cause spurious added/removed events.
fix jslint error. Fix getSourceFromBrowser response. Remove debounce for CSSDocument.
fix failing unit tests. restore CSSDocument initial call to _updateBrowser.