An ill-fated experiment with using a format that was closer to
Bazel left Blueprint preferring the original style, but documenting
and using the new style. Update the documentation and run bpfmt -w.
Test: builds
Change-Id: I3fb70c8fa50c332da01cf5912b179c60d1638814
Add globbing with dependency checking to blueprint. Calling
ModuleContext.GlobWithDeps or SingletonContext.GlobWithDeps will return
a list of files that match the globs, while also adding efficient
dependencies to rerun the primary builder if a file that matches the
glob is added or removed.
Also use the globbing support for optional_subdirs=, subdirs= and build=
lines in blueprints files. The globbing slightly changes the behavior
of subname= lines, it no longer falls back to looking for a file called
"Blueprints". Blueprint files that need to include a subdirectory with
a different name can use build= instead of subdir= to directly include
them. The Blueprints file is updated to reset subname="Blueprints" in
case we want to include subdirectories inside blueprint and the primary
builder has changed the subname.
Also adds a new test directory that contains a simple primary builder
tree to test regeneration for globbing, and runs the tests in travis.
Change-Id: I83ce525fd11e11579cc58ba5308d01ca8eea7bc6
