Initial implementation of hover preview delay:
* Changes providers so they're not responsible for showing popover. They
return an object with the info needed to show one later.
* Add a 'popoverState' object that can represent both visible and pending
(waiting on timer) popovers.
* Pending popovers can wait on both a timeout delay AND an additional
provider delay (needed for <img> loading). The wait can be canceled in case
a pending popover is invalidated before being shown.
Simpler, less disruptive hover preview delay: let image provider continue
to use its hack where it re-hides the popover as soon as it's shown (until
image loaded); no separate preloading of image; only delay popover based on
simple timeout (not compound of timeout + provider-specified delay).

Also, ignore mousemove when a drag is in progress.
Merge remote-tracking branch 'origin/master' into pflynn/hover-preview-delay

* origin/master: (105 commits)
  Minor fixes after review
  update HTML file extensions for smarty and twig file extensions
  String in case we want to add a "More" link to get to the extension's home page
  Fix GitHub case
  String requested by adrocknaphobia
  Update 'de' locale
  Reworked the text of getting started
  make sure hex values end on boundary
  implement updated project panel styles
  Fix regressions in the display of literals and keywords in code hints. 1. keywords should be monospace. 2. literals should be dark grey.
  add new identifier colors from Lawrence Hsu.
  Properly force the Extension Manager to retrieve the registry on every dialog open
  Explain whether incompatible extensions require older or newer versions of Brackets. Remove hard-coded app name references in strings.
  Updated by ALF automation.
  Externalize strings from Extension Manager view item template
  define offset in constant
  fix problem where jQuery was not recognized as a builtin
  Increase max image size to 200x200
  fixed padding
  add jquery api to hints
  ...

Conflicts:
	src/extensions/default/HoverPreview/main.js
Remove TODO and make 'lastPos' throttling official: in a quick test, it
reduces the number of events handled by 8-10x while moving mouse around.
Merge remote-tracking branch 'origin/master' into pflynn/hover-preview-delay

Still need to fix up Hover Preview unit tests to work post-merge.

* origin/master: (22 commits)
  fix permissions on french translation
  Export all hover preview functions as private functions to unit tests. Update test file with some repeating-linear-gradients, repeating-radial-gradients, and some invalid color names. Update unit tests with the correct cursor positions for all unit tests.
  test popover positioning
  Few cleanups for OpenLine's tests
  Remove Italian strings for OpenLine. Add little changes to tests.
  Updated by ALF automation.
  french getting started translation from sprint 23
  Include changes to OpenLinecode and new tests
  cleanup based on codereview comments:
  Adding image files used in unit tests
  Add unit tests for hover preview
  Add special case for last line in inline editor
  Initial test files creation
  Include TomMalbran's suggestions
  Remove cruft from the outdated stats-gathering branch.
  Add few improvements in OpenLine
  Fix OpenLine undo history
  Fix OpenLine problem with inline editors.
  Invert OpenLine shortcuts
  Improve Open Line feature. Add additional unit tests.
  ...

Conflicts:
	src/extensions/default/HoverPreview/main.js
Expose what's needed for unit tests from Hover Preview & its providers.
Update unit tests to use this new, cleaner way of getting info.
Disabled some gradient unit tests where the provider is generating nonsensical
CSS, pending resolution of #3535.
Merge remote-tracking branch 'origin/master' into pflynn/hover-preview-delay

- Be more explicit about testing the fix in pull #3482
- Add simple test for matched-text highlighting in UI
- Cite bug numbers for all disabled tests

* origin/master:
  fix unit tests for changes in this branch
  remove misguided attempt to filter gradients for Chrome 25
  code cleanup
  ignore new gradient syntax, for now
  ignore new gradient syntax

Conflicts:
	src/extensions/default/HoverPreview/main.js
	src/extensions/default/HoverPreview/unittests.js
Code review: remove unneeded div; split object literals onto multiple
lines; don't add set/clearTimeout() to JSLint globals
Consolidate code that checks if a pos lies within a range
Merge pull request #3531 from adobe/pflynn/hover-preview-delay

Delay before hover preview