Allow alternative dist directory

This implements the build requirements so that an alternative dist
folder can be used rather than `dist/`. Any folder is fine, and the
bundles will be placed in a folder `bundles/` underneath the dist
folder.
Updated bower to latest steal version
Merge branch 'master' into dist-dir

Fixes merge conflicts and tests
New steal version with css fix

This updates to the latest steal version which has CSS correctly work
with the distPath configuration option.