Major upgrade of events with numerous fixes

+ added event title field
+ fixed bug: event category was hidden and not really used (issue #32)
+ fixed several typos in EN/ET language files
+ also applied fix and tested (reported issue #62)..generally
works!...bugs: COM_STREAM_LABEL_FORAMONTH in a file
(stream.item.todo.edit.php, stream.item.event.edit.php)
+ added pinning option also to blog and milestone
+ unified the look of blog and milestone items in common stream
+ fixed bug that blog did not show categories