Project Specific ANT_HOME override feature

Hi list,

I recently ran into a problem where I needed different versions of ant 
to build different projects.  One workaround would have been to run two 
different anthill servers each configured with a different ANT_HOME, but 
that wasn't very flexible.  Instead I've added the capability to 
override the anthill default ANT_HOME at the project level.

I'd be happy to commit these changes to the CVS repository or send my 
changes to a maintainer for review and inclusion.

Here is a quick overview of my changes:
Added an ant.home.override property at the project level (in 
com.urbancode.anthill.ProjectProperties), and updated the related  
project properties UI files (servlets and JSP).
Moved the calculateAntHome method to the AnthillProject class - so it 
can decide whether to use the override of the anthill default.
Updated the BuildManager.buildProject() method to use the new 
calculateAntHome().

Please advise on if and how you would like me to submit these changes.

Sincerely,
Andre V