Instead of requiring a target, default to //polygerrit-ui/...; this
package and subpackages have several bower_components rules, and
using all of them is most likely to produce all the existing rules in
lib/js/BUCK.
Rewrite instructions in lib/js/BUCK so they are more copy-and-
pasteable. Add instructions to the generated new BUCK file on how to
merge with an existing BUCK file.
Normalize the existing package names so there's less delta on each
diff.
Change-Id: I5f46d4d06d6aaacf40c9a7771eec6e85710093e1
770d62e87f