Fix for ESC -> meta in terminal mode.

If you hit esc-key in terminal mode very quickly, it gets interpreted
as meta-key, which makes evil-mode unusable in terminal mode. The
default value of 0.01 doesn't completely fix this behavior, but
setting it to 0 does. The meta key still works fine with it at 0.
Merge pull request #613 from roryk/upstream

fix for evil-mode in terminal