When do "scripts" get updated for Virualmin Pro?

Several script versions listed don't match current release versions for the products. For example: 1) Wordpress is 2.03 (script says 2.02, but I'm pretty sure it just installed the 2.03 version even though it still says it is 2.02)

2) SquirrelMail is 1.50, but current version is 1.51 (some security fixes, etc).

So, two questions:

a) How to I upgrade something AHEAD of the official Virtualmin install (and get Virtualmin to recognize this) Specifically, I want to do the SquirrelMail upgrade, if you want to use that as an example

b) Any documentation on how the scripting process is setup, etc. so that I could dig aound and figure some of this out? (I'm a lightweight with linux, however).