Simple GetData implementation

please fix FIXME wrong unicode strings convertion
nsClipboard fixies

added outer-window-destroyed listener
truncate mBuffer after use
fix. Truncate mBuffer after use.
Do not use json for unicode strings. Light workaround.
Merge pull request #19 from CODeRUS/master

Simple GetData Clipboard implementation
[embedlite-components] Merge remote-tracking branch 'tmeshkova/master'