#27: Improved text selection behavior to select the word on double click and the line on triple-click.  Also refactored user events to contain the mouse buttons and key codes that were pressed when the event was generated.
#27: Fixed text element to have the right height event without any text content.
Also fixed a bug with double-click text selection.
#27: Fixed a bug in line selection
#27: Started multi-line support in text fields.  I seem to have broken the text field test pretty bad, may end up having to back this one out.
#27: Added multi-line support in text fields.  Added a multi-line text field to the text field test.