Maven build properties

[Steve T]

We have been using a plugin to do file replacements for a while, but
it makes a lot more sense to move to just using maven resource
filtering for configurable aspects of the application at build time.
We already use a resource file to supply our Spring configuration with
values at runtime and that technique uses the same syntax as the maven
resource filtering ${propertyname}.

In an effort to avoid collisions between build time replacements and
runtime replacements, I am going to start prefixing build time
configuration variables with "build", so that you will use $
{build.propertyname} for any configuration in a resource file that you
want replaced at build time by maven.