Override script in Application.generate()

Make it possible to override script in Application.generate() if necessary,
by providing a "script" option.  If it's not present, then use Application.script
Merge pull request #3 from sgillespie/master

Move autoconfigure tasks to project.tasks.addRule()
Merge pull request #5 from sgillespie/override-script

Override script in Application.generate()
Minor cleanup in prep for v0.2.0
Fixing issue with sonatype credentials
Remove creation of extra tasks

We were creating extra tasks from the autoconfigured task rules
even when specifying a bad fabric