Several Changes

[notslang]

I had an issue with js2coffee not being detected on my path after installing it (even though I used the install instructions provided and am able to run js2coffee from terminal)... So, I fixed that and ended up making several other improvements including:

• updated formatting to match pep8
• plugin now sets syntax of the output to coffee script automatically using set_syntax_file()
• plugin no longer opens a new file when js2coffee returns an error
• added option to overwrite current file rather than make a new one
• command caption clarified
• new command added to separate overwriting current file from making a new one

...and general refactoring

So far, I have only tested these changes on Linux (Ubuntu), so I am not sure if the path used to set the syntax file will break on Windows since it uses \'s (somebody who uses Windows should test this).

PS: Thank-you very much for writing this, it is hugely useful to me since I usually end up converting every piece of JS I come in contact with, into CoffeeScript.

[nibblebot]

very good! tested on OSX and it works fine with path finding. not sure why I was having trouble without setting path directly to /usr/local/bin I'll update the readme to reflect these changes