performance improvement

Conflicts:
	slick.grid.js
remove numberOfRows private member because it only used in UpdateRowCount.
remove not used variable
Merge pull request #725 from kzhdev/performance

Performance Improvement
Fix #744 - When multi-select is off, do not stop propagation on the shift-click event.
Add a grid initialization benchmark.
Undo an accedental edit.
Added Link to Github source

for all example pages in github pages
updated one missing source link
Merge pull request #781 from tobya/ghpages-GHLink

Link to Github Source from examples
Make idProperty configurable.
Instances of SlickGrid should not share one global EditorLock by default.

When SlickGrid is used as a part of an editor inside another SlickGrid,
sharing a global editor lock will close the editor unexpectedly.