Add InfoTips to various controls

Summary:
This adds most of the InfoTips listed here:
https://docs.google.com/a/khanacademy.org/spreadsheet/ccc?key=0Ai5zk7-i2CKkdC1kU21uMzhCNExReUdpemJJenRsTGc&usp=sharing#gid=0

Except for the ones under Text Input (number) for which there is a note
saying just to use the default "Numbers" one.

Test Plan:
  * For each of the InfoTips provided in the linked spreadsheet, check
    that the InfoTip appears in the right place with the right text.

Reviewers: alex, jack

Reviewed By: alex

CC: alpert, jack

Differential Revision: http://phabricator.khanacademy.org/D5841