Update index.htm

Additions:
jquery-ui for adding new subscriptions
font-awesome for icons
Update style.css

removed mobile-sprint.png
added some jquery-ui and font-awesome tweaks
Update g2tt-config.js

added pref_Feed_limit for easy access to change limit. Want to use jStorage in future so multiple users can change per user.
Update index.htm
Update g2tt.js

added subscribe to new feed and other tweaks
Avoiding merge conflics with mrjeremey28
Merge branch 'master' of https://github.com/mrjeremy28/g2ttrss-mobile into mrjeremy28-master
Removing mrjeremey28 specific stuff (mudreader)
Beautify
Restore gray back ground; Override jguery style on sign in button