PRD-4380: Fix a simple IOOB-exception in formula dialog
PRD-4500: FormulaExpressionEditor must start empty formulas with "=" to give users a headstart.
Removed subfloor copy from root. The multi-build file we use is more lightweight and works fine within the various sub-sections already. Also created a copy named as "build.xml" so that developers and users can invoke it directly.