Move calendar/color picker CSS/JS resources from core to web

These files are only referenced in Source/web/, not in Source/core/, so
putting them in the (new) web/resources/ directory seems to make more sense.

Also moves the script used to generate these files in web/scripts/,
and makes the rules properly treat the script as an 'input'.

R=abarth

Review URL: https://codereview.chromium.org/25657009

git-svn-id: svn://svn.chromium.org/blink/trunk@158786 bbb929c8-8fbe-4397-9dbb-9b2b20218538