Fix problematic comparisons in grid.search function

Function w2grid.search(field,value) receives the value coming from w2fields.clean() which returns a value of type 'number'. When the search condition is explicitly 0 (i.e., zero, which is common, such as in a search of a two-valued field, like a boolean) the comparison

(val !='')

which occurs at several places in the function, returns false, although 'val' is actually a valid value. The correct comparison is (val !=='').
This fix allows for searches of 0 either in the 'toolbar Search' as well as in the 'Search Popup'
Merge pull request #690 from sairum/gridsearches

Fix problematic comparisons in grid.search function
Some minor bugs
Implemented focus/blur for grid and sidebar
Toolbar enable/disable can now enable and disable menu items.
Recompiled JS and CSS
Small documentation fix
Removed hasFocus property form grid and sidebar
Recompiled JS
Fixed issue #689
Recompiled JS
Added events to routers (onAdd, onRemove, onRoute)
Fixed some bugs in grid search fields
Fixed bug with popup close on mouse out
Recompiled KickStart
Recompiled JS