Reduce searched fields for datacolumn. For issue #161
Show paperproposals in dataset overview page. For issue #160
Fix performance issue with the migration merging date types. For issue #68
revert a change that causes builds to fail.

I thought i forget to change the value before, but it turns out to be left
for a test.

I forgot to run test before push.
updated rails as version <3.0.18 suffer from sql-injection vulnerability