Merge pull request #3 from SCIF/master

Phpdoc and  code style improvements by alexander
Merge pull request #4 from SCIF/master

Added add*type*() shorthands to DataForm.  Added fixes for DG output
basic datafilter class/ logic / persistence, untested
basic datafilter class/ logic / persistence, untested
debug
rollback,  DataFilter must accept different source type, override source() with different type throw ErrorException otherwise
conflict
check
renamed session manager
fix
damn facade fix
Allow add to form only fields which inherits of Field class
Introduced basic i18n support. Translated DataEdit buttons