Revert "Don't anchor :dia completions". The reason we anchor :dia, is that once you know which :dialog you want to open, you can usually open it with :dia xy<tab> very quickly and reliable. The difference to :emenu is that :emenu has lots of completion items with the same prefix, so anchored completions wouldn't really be that helpful to quickly open a menu.
Revert "Don't anchor :dia completions". The reason we anchor :dia,
is that once you know which :dialog you want to open, you can usually
open it with :dia xy<tab> very quickly and reliable. The difference
to :emenu is that :emenu has lots of completion items with the same
prefix, so anchored completions wouldn't really be that helpful to
quickly open a menu.

This reverts commit fa842fd716aac599891a53efdf64cab76422c153.
smarter/vimperator-labs