FLUID-5120

Replacing ant based build scripts with grunt. For the most part the builds have been translated in kind, however there are several features that have been removed, at least for the time being.

1) css generation for the preference framework (This will be revived after a css preprocessor, less or sass, has been chosen, and the themes rewritten)

2) url rewriting (This is used only for release testing. It is something that should be brought back in the future.)

3) The names for the builds, as well as the command line arguments have also changed slightly. 

(See the included README.md for build instructions)

http://issues.fluidproject.org/browse/FLUID-5120