Gettext files support in Atom

Adds syntax highlighting to msgid, msgstr, etc in Atom.

Adds a few snippets:

• hdr -> "$1: $2\n"
• id -> msgid "$1"
• idp -> msgid_plural "$1"
• str -> msgstr "$1"
• strp -> msgstr[$1] "$2"
• ctx -> msgctxt "$1"
• msg -> msgid + msgstr
• msgp -> msgid + msgid_plural + msgstr + msgtrp_plural
• msgc -> msgctxt + msgid + msgstr
• msgcp -> msgctxt + msgid + msgid_plural + msgstr + msgtrp_plural

The last tab navigation position is conveniently placed on a new line so you can chain quickly.

Originally converted from the Gettext TextMate bundle.

Contributions are greatly appreciated. Please fork this repository and open a pull request to add snippets, make grammar tweaks, etc.