Fix Safari 6 toString() bug

Merged from https://github.com/jaywilliams/SlickGrid/commit/6b8de2183491408e1d89ed7c7981c24d9f276dc2.
Applied fix to destroy error with JQuery 1.9.
Merge pull request #597 from beckstea/JQuery-1.9-Fix

Applied fix to destroy error with JQuery 1.9.
Stop propagation of click event in showMenu

Stop propagation of click event in showMenu as otherwise the column
sorting is triggered
Merge pull request #607 from wienand/master

Stop propagation of click event in showMenu
Add functionality to AutoTooltips to optionally work for header cells. Add tests for AutoTooltips.
Add example to demonstrate AutoTooltips.
Add link to AutoTooltips test.
Fix test and clean up.
Clean up file.
Merge pull request #611 from mckramer/autotooltips2

Enable AutoTooltips plugin to work with header cells
Fix #418 - header menu icons not visible in FF when used with sortable columns
Merge remote-tracking branch 'upstream/master'

Conflicts:
	slick.grid.css