Fix LWUIT key release issue.

`com.sun.lwuit.Display.keyReleased` is never been called which causes
`com.sun.lwuit.Form.keyRepeated` is invoked repeately.
Merge pull request #573 from PinZhang/pzhang/keyrelease-issue

Fix LWUIT key release issue.
Merge pull request #559 from PinZhang/pzhang/texteditor-focus-issue

Fix LWUIT text editor focus issue.
Implement password editor.
Fixed regression: the caret position lost.

caret position is lost in the case:
  - Edit TEXTAREA field, input some character
  - Edit PASSWORD field
  - Edit TEXTAREA field again, the caret lost.
Add testcases for PASSWORD editor.
Move libs/text_editor.js to midp/text_editor.js