One direction pinch zoom
Increase touch zoom anim duration
Merge pull request #383 from elemoine/pinch-direction

One direction pinch zoom
Factor out core elements of ol.TileQueue into ol.structs.PriorityQueue
Refactor ol.TileQueue to extend ol.structs.PriorityQueue
Replace isHeap with assertValid
Add optional per-tile callback to manageTilePyramid
Store focus in frame state
Add tile texture queue
Use tile texture queue
Tune tile priority functions
Make tile pre-loading a per-layer option
Add preload example
Set preload appropriately in examples
Make preload a number of levels instead of a boolean
Correct preload example tags, thanks @fredj
Don't attempt to install PhantomJS on Windows

Instead, assume that phantomjs.exe is already in the user's path. It can
also be overridden on the build.py command line:

  build.py PHANTOMJS=path/to/phantomjs

or with an environment variable:

  set PHANTOMJS=path/to/phantomjs
  build.py
Merge pull request #441 from twpayne/dont-install-phantomjs-on-windows

Do not install PhamtomJS on Windows
Fix build/src/external/src/types.js dependency

The dependencies for build/src/external/src/types.js were wrong, which
meant that build/src/external/src/types.js would always be rebuilt,
which meant that almost everything else would be rebuilt too.
Merge pull request #442 from twpayne/fix-types-js-dependency

Fix build/src/external/src/types.js dependency