Leave the down_ event set

The other "up" type listeners (for touch and pointer) do not set this to null.  This event can be of use to a click listener that might want to compare the down position to the click event's position.
Provide a method to get the most recent down type event

This will allow interactions to conditionally handle later events based on the down event.
Make interactions event targets
Fix 'change' event name in apidoc
make some minor fixes to the parser test cases, such as using afterLoadXml everywhere and making sure done is used in all async tests
Fix singleclick and doubleclick on windows Surface
Forbid right click to trigger singleclick events on IE10
Modify comments
Merge pull request #1253 from tschaub/interaction-events

Make interactions event targets.
use plain XMLHttpRequest instead of goog.net.XhrIo
make tests pass in the test runner as well by not checking for status code
Merge pull request #1254 from bartvde/parsertests

change the afterLoad utility test functions (r=@elemoine,@tschaub)
Merge pull request #1248 from fredj/apidoc_changename

ol.Object.getChangeEventType and key.toLowerCase
Call setRenderIntent on the feature, not the layer
Add a getFeatures method on the vector layer
Do not use a temporary layer for selected features
Removing no longer used getFeatureWithUid method
Make selectedFeaturesFilter available to other components
Do not fail on non-vector layers
Merge pull request #1231 from oterral/mouse_events

Fix touch events on IE10