Add support for help_pre in addition to help_post for profile fields

See http://forum.civicrm.org/index.php/topic,12159.0.html

Custom fields have both help_pre and help_post.
Profile fields have only help_post, leading to nasty template hacking to get the relevant help text displaying in the right places.

Discussed on IRC today (times in GMT):

[16:40] dlobo: davej_: u committing to adding support for uf_help_pre?
[16:40] dlobo: for 3.2?
[16:41] dlobo: if so, file an issue and we'll add to schema (or u can also do it
[16:43] dlobo: davej_: u can add to schema in xml/schema/Core/UFField.xml
[16:43] dlobo: and then run GenCode.php etc, which u've done
[16:44] dlobo: dgg: i assume this is fine, right? has come up before a few times
[16:44] davej_: dlobo: I was thinking if the schema change can go in, then I'll try to do the code when I have time, for 3.2.x where x > 0
[16:45] dgg: it's fine, altho we might want to tweak the Profile Field form ui and bit so we don't have both large textareas open by default
[16:45] davej_: - You only do schema changes in major versions, is that right?
[16:45] dgg: since that forces lots of scrolling to see the other properties
[16:45] dlobo: davej_: file an issue, i'll do the schema change. but we'd really really like it if it goes in before 3.2.0 beta
[16:45] dlobo: davej_: we try to do most schema changes before the release
[16:47] davej_: dlobo: OK, I'll file an issue and have a go. Haven't done the gencode thing for a while. Guess I need to grab current svn - trunk?
[16:48] dlobo: yeah

Dave J