active_record: Quote numeric values compared to string columns.
Merge pull request #9209 from dylanahsmith/3-1-mysql-quote-numeric

[3.1] active_record: Quote numeric values compared to string columns.
Fix test failure for ruby 1.8
Merge pull request #9226 from robertomiranda/fix-bigdecimal-test

[3.1] Fix test failure for ruby 1.8
Fix issue with attr_protected where malformed input could circumvent
protection

Fixes: CVE-2013-0276
bumping to 3.1.11
Update changelogs with version/release dates [ci skip]

Also add note about attr_protected change.