Add fixme/todo target to build.py.

Will show a list of lines in sourcefiles that either contains the string TODO
or FIXME.

Example output:

    user@host:~/src/ol3 $ ./build.py fixme
      src/ol/source/xyzsource.js has 4 matches:
        #1         // FIXME add minZoom support
        #46        // FIXME use goog.nullFunction ?
        #59        // FIXME factor out common code
        #76        // FIXME we shouldn't need a typecast here

      src/ol/interaction/dragpaninteraction.js has 2 matches:
        #1         // FIXME works for View2D only
        #39        // FIXME works for View2D only
Merge pull request #154 from marcjansen/todo

Add fixme/todo target to build.py.
Test if browser supports Windows Pointer events
Direct all pointer events to js code (IE pointer events).

see: http://msdn.microsoft.com/en-us/library/ie/hh673557(v=vs.85).aspx
Merge pull request #157 from fredj/ms-touch

Direct all pointer events to js code (IE pointer events)
see: http://msdn.microsoft.com/en-us/library/ie/hh673557(v=vs.85).aspx
Add a comment about msTouchAction css on viewport
Add missing goog.events.EventType.DBLCLICK argument to unlisten
Remove event listener with goog.events.unlistenByKey
Don't remove event listener for this.handleUp_ twice.

The listener key is in this.dragListenerKeys_
Remove event listener with goog.events.unlistenByKey
Do not draw image if image is null
Merge pull request #161 from elemoine/nullimage

Do not draw image if image is null
Merge pull request #160 from fredj/dblclick-unlisten

Remove event listener cleanups
add info about install Jasmine and the precommit hook from build.py
Always dispatch change events on load/opacity/visible changes
Promote dispatchChangeEvent from ol.renderer.webgl.Layer to ol.renderer.Layer
Promote handleLayerRendererChange from ol.renderer.webgl.Map to ol.renderer.Map
Promote renderFrame from ol.renderer.*.LayerRender to ol.renderer.LayerRenderer
Change class names in DOM renderer
Change a comma to a semi-colon (thanks @bbinet)