Beer xml updates

1. Move the open action to it's own action bar icon (that goes away with the new icon)
2. Use toast notifications rather than dialogs.
3. Move BeerXML to two seperate AsyncTask classes, one for reading, one for writing.
4. Fix the BeerXML BJCP Category import.

With #4 I'm confused as to why the BJCP Categories don't hold the OG/FG/IBU/etc... since those are defined in the relevant years info.