[SHELL32]

[SHELL32]
- Add DoDeleteAsync method that takes the data object and the fMask parameter from IContextMenu in order to distinguish if we need a permanent delete.
- CDefView: Properly add CMIC_MASK_SHIFT_DOWN and CMIC_MASK_CONTROL_DOWN flags when calling Invoke.
- CDefaultContextMenu: use DoDeleteAsync and pass fmask so as to make Shift+Delete shortcut to permanently delete files.
Note: GetKeyState sometimes returns wrong results but this doesn't concern the shell.
CORE-4365

svn path=/trunk/; revision=69647