Fetch innodb stats from the information_schema when appropriate.

This supercedes #556, using the same query but assigning types.
I'd love some help deciding which types to use.
Merge pull request #824 from collectd/feature/update-innodb-stats

Fetch innodb stats from the information_schema when appropriate.
Merge branch 'master' into debian
updating build.sh results
Merge branch "debian" into debian-wheezy-backports