Select all the text when moving focus on a line edit by TAB key.
Move the focus backwards with SHIFT+TAB.
On LineEdit move around the borders of current selection.
Minor improvement and bug fix on some of the UI elements.

Also:
- Focusable UI elements appears with a consistent visual "focus rect" when in focus.
- Make more UI elements focusable. It is now possible to cycle through all the editable elements using Tab key (in general dialog window or in Attribute Inspector).
- Closes #94.
Merge remote-tracking branch 'remotes/reattiva/ui_practices'
Add the byKey parameter to script bindings of SetFocusElement().
Travis CI: API documentation update at 2014-01-03 19:53:08 UTC.
[ci skip]