Allow user to enter commands as bookmarks.

Previously, bookmarks where converted to KUrls and then only protocols
Konsole knew about internally were processed.  Now if a bookmark has no
KUrl protocol, Konsole just sends the bookmark to the shell.
This will solve issues such as 'ssh user@server -p port tail -f file'
as well as allowing any command to be a bookmark.

BUG: 88867
BUG: 203263
BUG: 253894
BUG: 185962
BUG: 213644
FIXED-IN: 4.6.2