After the folder's context menu closes the folder tree selection jumps
back to the folder whose contents are showing in the message list.
Suggested by Philippe LeCavalier on evolution-list.
This addresses bug #593896 but is also a cleaner design than before.
It introduces an EShellView::execute-search signal and renames the
"search-execute" action to "search-quick" to clarify that it's only
meant for the "quick" search bar in the main window.
Shell view subclasses should implement the execute_search() method to
actually execute a search.
e_shell_view_execute_search() emits the new signal.
common to both the main shell window and the message browser. Replaces
EMFolderView. Also begin to define EMailBrowser (GtkWindow subclass),
which implements EMailReader and replaces EMMessageBrowser.
svn path=/branches/kill-bonobo/; revision=36933
