orch: inject top project directory into worch.env
example: use top-dir variable
Add a cmake version of the autoconf feature.

This has a lot of cut-and-paste overlap the should be factored out.
Merge branch 'master' of github.com:brettviren/worch
Fix string vs. list regression.
Quiet down
Building up through ROOT with some problems still to iron out.
Add production of a graphviz dot file of the tasks and files making up the dependency graph.
Tweak a bit the context in which dot runs.
Make proper dag objects and add a test.
Merge branch 'master' of github.com:brettviren/worch

Conflicts:
	orch/dot.py
Add package subgraphs, fix stuff.
Add group dependencies.
Merge pull request #16 from hwaf/dev/inject-topdir-variable

Dev/inject topdir variable