* Divide gulp targets into three kinds: main sequence,
manually invokable, and script-only. The first two categories
automatically invoke their prerequisites.
* Give (most of) the affected gulp targets shorter and more memorable
names that could become their npm script names in future.
The documented release process is to do npm run recompile, merge the
resulting branch to develop, and then do npm run relase, which does
not do another build.
This process should probably be changed, but for the moment ensure
that npm run recompile (as well as npm run package:beta) runs
buildTasks.checkinBuilt after each .build to preserve the old procedure.
