CORE-5732 Added a clear method to LiveGridCheckBoxSelectionModel.

Updated DiskResourceViewImpl to call this clear method, which will clear the model's selections, every time a new folder is loaded in the center grid.
Set the grid's cache size smaller, to cut down on load times, now that listings take a little longer with favorites icons and the like.
Minor refactor in LiveGridCheckBoxSelectionModel#isSelected (itemKey only needs to be calculated once).
CORE-5723 Fix for Firefox live grid row heights.

Always use a row height of 25 for now.
Updated iplant_ui_layer_eclipse_codestyle.xml

Updates to allow types and parameters to align in a column.
Applied UI code style formatting to LiveGridCheckBoxSelectionModel.java