add support for number and date rages

- by default, all numerical and date fields now use a range slider
- jQueryMobile supports numerical ranges but not date ranges, so I
modified it to support them.  I couldn't do this by extending the
javascript so I modified the source instead.  All changes are tagged
with MOBILE-FUSION-TABLES comments in case anyone upgrades jQueryMobile
in the future.
Merge branch 'master' into gh-pages
update demo files to point to new scripts