Added the ability to compare all tables in two ROM images.

Usage:
 - Open one or more ROM images (The same image can be compared to itself.  Will not do much but show "Images are equal.").
 - Select edit->Compare Images...
 - Select the two images to compare and click the compare button.
 - Results are displayed in the results pane.
 - Added ability to open multiple images
 - Added ability to save as repository.  This basically dumps the tables into a file structure represented by the categories and saves the tables as a text file.  I use this for tracking changes made to my ROMs using revision control.
 - Divider now repaints when moved.
 - Opening a new ROM image now properly expands the added ROM tree.
   - Note: Uncomment ECUEditor:289 "imageList.collapsePath(addedRomPath);" to open new ROM image collapsed.
Runs "Copy Table" routine as a SwingWorker.  This should allow the UI to complete the copy without hanging the UI thread.
 - Fixed bug where null exception is thrown when the enter key is hit an no image is open.
 - Added ability to open a table by highlighting and then hitting the enter key.
 - Fixed unhandled exception when user hits ctrl+ENTER with no data or bad data in the multiply text field.
 - Changed variable from foo to tableFrame.  I find that tableFrame is more descriptive.
 - Added ability to use space as well as enter to open the selected table.  Using space seems to retain the selected table where enter instead shifts focus to the top level ROM node.
 - Changed "Copy Selection" to use a worker thread.
 - Fixed unhandled exception when attempting to parse the input int DataCell.java.
Fixes bug where focusing on a table does not switch the toolbar tooltips and menu item text to display the currently selected ROM.
removing duplicated code.
Duplicated Code
Incorporate scotthew updates
Release Candidate 0.5.6 RC2
Fix Linux ZIP install startup script
Added lines to include missing Phidget & TXS UTEC plugin files in installer packages
 - Simplified table toolbar logic.
 - Table toolbar now updates the overlay Log checkbox properly.
Debug update to dump ROM ID info of all configured Editor defs
Fixed calculation problem for derived parameters with non-characters in their abbreviation. Also corrected units abbreviation.
Fix as Linux complained if internalStringId was not initialized in ROMID class
Release Candidate 0.5.6 RC3
Remove some unused constructors/fields/variables.