Add whole word matching for CtrlPSameName

Files with names that are common substrings are hard to find with
CtrlPSameName. Add an N variant that searches for whole words.

Update A-o related uses to require whole word match. That's probably
what the file's called. If not, I can use C-o n to non whole word match
(which is easier to type than C-o N).
Perforce: Files aren't always in depot

When using streams, files are usually in a depot named after the stream
instead of the default "depot".
Add quick usage to p4reconcile
sub: Update searchsavvy to use extended regex

Makes vim to grep conversions work when using bar for OR.