Add Modernizr 2.7.0, update description and maintainers

Source:
http://modernizr.com/download/#-fontface-backgroundsize-borderimage-bord
erradius-boxshadow-flexbox-flexbox_legacy-hsla-multiplebgs-opacity-rgba-
textshadow-cssanimations-csscolumns-generatedcontent-cssgradients-cssref
lections-csstransforms-csstransforms3d-csstransitions-applicationcache-c
anvas-canvastext-draganddrop-hashchange-history-audio-video-indexeddb-in
put-inputtypes-localstorage-postmessage-sessionstorage-websockets-websql
database-webworkers-geolocation-inlinesvg-smil-svg-svgclippaths-touch-we
bgl-shiv-cssclasses-addtest-prefixed-teststyles-testprop-testallprops-ha
sevent-prefixes-domprefixes-load-dontmin

Updated maintainers and description to match source website.
Merge pull request #2223 from petecooper/master

Add Modernizr 2.7.0, update description and maintainers