Deprecate the use of mirrors.xml

Thanks for making this, it's been really useful. I was reading the docs
and the TVDB API now handles it's own load management, so there's no
need to request mirrors.xml or retrieve one at random.

http://thetvdb.com/wiki/index.php?title=API:mirrors.xml

Remove unnecessary bit masks
Merge branch 'deprecate-mirrors-xml' of https://github.com/shaggythesheep/api-thetvdb into deprecate-mirrors-xml
/com/omertron/thetvdbapi/model/Mirrors.java

Conflicts:
	src/main/java/com/omertron/thetvdbapi/model/Mirrors.java