Fixed Bug: Small buttons are not visible initially.

Small ugly buttons were visible before searching. Their default
visibility is set to false.

Change-Id: I54baf50e4ffd7749391fbc0a48a07d7a1ffd5433
Moved the application of persona process to SelectPersonaDialog.

The theme is downloaded now when the user clicks OK on
SelectPersonaDialog instead of SvxPersonalizationTabPage. The task
is done in a separate thread.

Change-Id: I93173cce2ae9030ee8e271bd53b40e713c560731