Support option overrides and test skipping

[iay]

WIP:

• Reworked README to be clearer, and add documentation for overrides.
• Supports option overrides in general based on endpoint name matching.
• Supports skip: true.

[alexstuart]

I like this a lot & approve (in both senses of the word).

Two nits:

1. line 57 you typoed "imlementing"

2. lines 60-62 you write

v09x represents the current production deployment. Its name reflects that environment's composition: v0.9.x of the Shibboleth Metadata Aggregator, and the Xalan XSL processor included in the classpath.

You're using using x to signify "with Xalan" and also "a patch version". Might be clearer if you don't add the patch version.

[iay]

v09x represents the current production deployment. Its name reflects that environment's composition: v0.9.x of the Shibboleth Metadata Aggregator, and the Xalan XSL processor included in the classpath.

You're using using x to signify "with Xalan" and also "a patch version". Might be clearer if you don't add the patch version.

Oh, good catch. I will just say v0.9 in this case, and fix up the other thing. Cheers.

[iay]

Pushed another commit to fix those issues. I'll squash it into one of the others before merging.