2.1 version released

Final release 2.1 available
- changed TreePanel behavior when selecting multiple nodes: now popup menu is showed in this case too
- fixed problem in QueryUtil when using filtering grid with multiple values and is null operator
- improved grid/form value object analysis: now multiple instances of the of the same class are managed
- added "getLazyInitializedAttributes" to Form panel, in order to define attributes to skip on managing Form's value object
- added HH_MM_SS_SSS and HH_MM_SS_SSS_AAA masks to Resources class, in order to support times expressed with milliseconds too
- fixed problem with TextAreaColumn when setting maxCharacters property
The distribution includes also Jar file libraries, source files, javadoc, licence and readme.txt installation instructions.