Added basic search

[icereval]

Basic search functionality we worked on Saturday w/ a few additions.

• Force the view to redraw on keyup/filter, this prevents a row which happens to end up in the same position after filtering from remaining indented
• Remove expand/collapse if depth is 0, alternatively might want a flag to indicate sorted/flat view.
• Added check for args.grid as this was failing a qunit test.

Note: Tree.prototype.sort will need to be reviewed as sorting has flattened the folder/file list and the results appear out of order due to hierarchy.

[sloria]

Thanks for your help with this!

I made a few small adjustments:

• searchInput is saved as an attribute of HGrid.
• searchFilter takes the current search text as a second argument, so the developer doesn't have to pull the value themeselves.
• searchFilter is an optional parameter. It searches by name by default