Fix ST3 issues and command panel

Hi - I've found several issues in ST3 and tried to fix them. The issues are:

1. The Ctrl+Alt+T command panel does not show up in both ST2 and ST3
2. \p(\n) does not work in ST3

What I've changed:

1. decode() is removed from strings in Python3, as well as the string-escape codec. I've removed unnecessary encoding and decoding so the code works for both ST2 and ST3.
2. ST3 does not allow calling show_quick_panel from on_done, so we need to work around with a timeout (http://www.sublimetext.com/forum/viewtopic.php?f=6&t=10999).

I've tested on ST2 and ST3 on Windows. This won't be compatible with older history files, but should work well after clearing the history.

Thanks,
Yuxiu