Tags - various bugs fixed.

Fixed the follwing problems
- when closing the split dialog the focus goes to the tag field and not to the memo field
- if the user writes in the tag line edit the name of a closed tag or of a tag already included in the transaction then an information modal dialog
will appear and the line edit will be cleared.
- use the painting context to restore right the color for text in the ledger

Patch provided by Alessandro Russo.

REVIEW: 107373