SetPositioning exposition in the API

The method in ol.Overlay is not exposed whereas is equivalent
getter getPositioning is visible in API and documentation.
The PR add a line of description to the documentation and expose
the method
Align pixels when drawing icons or shapes

The floor before setting the transform ensures that we translate by integer pixels for odd and even dimenstions.  The round before drawing the image ensures pixels are aligned.
Merge pull request #1077 from ThomasG77/setPositioning

Export ol.Overlay#setPositioning
Fix a bug when frameState is null which occurs in offline mobile devices
Merge pull request #1133 from tschaub/align-pixels

Ensure that pixels are aligned when rendering icons.
Merge pull request #1136 from pagameba/null-framestate-bug

Fix a bug when frameState is null which occurs in offline mobile devices.
Use integers when positioning on the target canvas

This avoids blurred images after view center changes (dx, dy)
and at fractional zoom levels (dw, dh).
Merge pull request #1135 from ahocevar/no-blur

Use integers when positioning on the target canvas
Add new condition param to ol.control.DragBox
Make sure that the event position is correct for touch events

This is a workaround for https://code.google.com/p/closure-library/issues/detail?id=588
Merge pull request #1138 from fredj/touch_pixel

Make sure that ol.MapBrowserEvent#getPixel() always returns a valid value
Merge pull request #1137 from fredj/dragbox_condition

Add new condition param to ol.control.DragBox
Do not relay contextmenu events
Do not relay mousemove events
Use jQuery to listen to map mousemove in examples

This commit also removes the click listener, which was used for touch devices. The click listener will be added back when the lib will correctly handle clicks on touch devices.
Emulate click and dblclick on touch devices
Make overlay container stop touchend and mouseup
Vector examples display feature info on click again
Do not relay mouseout events
Unconditonally set the framestate focus