use Ruamel's YAML library and add command-line flags, and more

[tb3088]

This amounts to a near total rewrite.

• multitude of command-line args
• use the Ruamel library which actually tracks the current spec and not an orphan
• split-out filepath expansion and data merging
• properly hook Logger in exceptions

crank version to 3.1

[alanjds]

This seem very nice. Do you mind why the tests are broken?

[tb3088]

haven't looked at it. Not an experienced Travis/Github user.
so python 2.x doesn't like 'exception from xxx' syntax.
And in python 3.x since I re-implemented my own version of some of the Logging() functions I have a class name conflict which I had hacked around by renaming a symlink in Python Class path.

I need to clean up at least the last one. Not sure I care about supporting python 2.x