IN PROGRESS ON JIRA: Add "Age" to demographic form on Advanced Search

[sonicthoughts]

Birthdates are very useful for smartgroups.  We used this http://wiki.civicrm.org/confluence/display/CRMDOC/Search+on+Gender+and+Agebut seems to break the site see CRM-15816 .  Adding Age to the demographic section should avoid the need for this code entirely and think it would be very useful.  The form is already using relative dates but requires a hard coded range.

[sonicthoughts]

Just informed that this is planned: https://issues.civicrm.org/jira/browse/CRM-16160