[EFL] PlatformKeyboardEvent: figures, letters and printscreen key handling

[EFL] PlatformKeyboardEvent: figures, letters and printscreen key handling
https://bugs.webkit.org/show_bug.cgi?id=85503

Patch by Mikhail Pozdnyakov <mikhail.pozdnyakov@intel.com> on 2012-05-16
Reviewed by Gustavo Noronha Silva.

Source/WebCore:

* platform/efl/EflKeyboardUtilities.cpp:
(WebCore::addCharactersToKeyMap): aux function
(WebCore):
(WebCore::createKeyMap): Figures and letters keys are added to the keyMap
(WebCore::addCharactersToWinKeyMap): aux function
(WebCore::createWindowsKeyMap): Capital letters keys are added to the windowsKeyMap. Corrected value for printscreen key.
(WebCore::singleCharacterString): Return empty text for printscreen key.

LayoutTests:

Bug-related testcases are unskipped.

* platform/efl/Skipped:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@117238 268f45cc-cd09-0410-ab3c-d52691b4dbfc