Changed mod_hl2mp_english.txt to include more strings.

Most notably I added the localization data for chat messages.
I stripped out the special characters to prevent git from detecting the file as a binary (git attributes didn't appear to work for this) but github doesn't seem to pick up on it anyways.
To view the file anyways you can use this link:
https://github.com/LaylConway/source-sdk-2013/blob/master/mp/game/mod_hl2mp/resource/mod_hl2mp_english.txt