Cleanups, mainly to unit tests:
- Improve docs in SpecRunnerUtils
- Add assertion in SRU in case a mock Document is created without an Editor
but then used in a way that would auto-create an Editor (which won't get
cleaned up)
- Add assertion in _destroyEditorIfUnneeded() since its name makes it easy
to call with the wrong type (including via SRU.destroyMockEditor())
- Rename HTML code hints suite & remove unused var
- Minor docs cleanups in LanguageManager (incorrect usage of "i.e.", missing
docs for new fileNames option, etc.)
- Add unit tests for install dialog cases where installer comes back with a
result after clicking Cancel but before Cancel times out, or comes back
vary late after timeout once user has opted to close the dialog
- Remove a duplicated LanguageManager test (due to f67cfcdf)
- Add a few more StringMatch tests to ensure tricky cases don't break in
the opposite direction as before
Cleanups:
* DocumentManager: use CollectionUtils.forEach() in notifyPathNameChanged()
(removing early-exit optimization that's probably unneeded; can reintroduce
when CollectionUtils.some() lands)
* Move filename->language mapping tests from Editor-test to LanguageManager-test
* Add another #330 testcase as suggested by Glenn in #3064
* Add StringMatch testcases as suggested by Kevin in #3417
* SpecRunnerUtils: use waitsForDone() more
* CSSUtils-test: remove unused vars
* Dialogs: tiny docs improvement
turn on cm gutter filler
Merge remote-tracking branch 'origin/master' into randy/cm-gutter-filler
use @background-color-3 for scrollbar and gutter fillers
Merge remote-tracking branch 'origin/master' into randy/cm-gutter-filler
Merge remote-tracking branch 'origin/master' into randy/cm-gutter-filler
bg images for mac scrollbars
more bg images for mac scrollbars
better win filler color
bump to 15,000 for now
Find in Files Pagination
Fix tab issue
Added CMD_SHOW_IN_OS and CMD_FILE_DELETE translations
move inline js into external files
add std license header and placate jslint
reorganize Readme

Moved paragraphs around so least technical (most user-oriented) is on top, then tech/contributing (hacker info) is near the end.  This allowed to streamline the prose, but I tried to avoid changing the text as much as possible.

Linked blog in welcome section (great for finding features; helps users decide if Brackets is for them).

Used H4 vs **bold** for sub-headers.
more terse, less repeated text

(note to self; don't Push with only 4 hours of sleep)
more terse, less repeated text, ordered helping steps
add comment for future about no inline scripts