Allow Build REST API to receive custom parameters

It'd be great if when triggering a manual build through the build API, if custom parameters could be passed in. These parameters could then be used to substitute values in the builder configuration for example. For example, if I have a build that releases some software, I might have my maven 2 builder configured to say mvn release:prepare release:perform -Drelease.version=${bamboo.release.version}, and then when triggering the build via the remote API, I might say bamboo.release.version=1.1. Any parameters that start with "bamboo." would be passed into the parameters of the build. Then my external release management tool (JIRA) could tell Bamboo to perform the release.

Note, I've checked out the implementation for this already, it's an incredibly simple thing to implement passing in custom parameters to the build execution manager.