Vim: remove an -nargs=0 option from a command declaration

Because -nargs=0 is actually the default.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Vim: add Acks command, for doing multi-file find/replace

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Vim: update Command-T to 1.5 release

Signed-off-by: Wincent Colaiuta <win@wincent.com>