.gitignore: ignore gvim swap files.
Bind F8 to HistorySearch*, similar to cmd.exe.

It's not /exactly/ the same as cmd.exe. For instance, it doesn't cycle
through results, but since you can use Shift+F8, to go the other way, it
still gets the job done.
Merge pull request #136 from jazzdelightsme/master

Bind F8 to HistorySearch*, similar to cmd.exe.