Removed copying smoketest source to EPOCROOT from sf-build-smoketestpkg target

Changed the way that the sf.spec.sourcesync.enable property is used to control the syncing, so that it can sync test repos even if it's not syncing any source repos.

Move targets round so that those related to syncing the source are all together.

Intelligent way of getting timings for ALL uses of sf-zip-content

Removed changes in build.test.xml to copy smoketest source to EPOCROOT

Removed copying smoketest source to EPOCROOT

Added stopwatch tasks through most of the code hit during a platform build.

Added sf-scrub-build, for completely freeing up the resources used by a build (ie deleting it from the HD). Removed import of generated ant script as it had no effect, and was causing strange failures with sf-scrub-build.

Removed check for value of PDT_HOME, as it doesn't matter where it's installed, and it's turning the CI builds red.

Code to automatically find a physical drive for running a build, triggered as necessary.

Added new logic to deal with drive letter allocation when builds are launched from Hudson.

Added framework for specifying a "sources.csv" for test repos (separate from both the FBF and the sources repos).