state: cleaner env config generation in EnvironSuite

A small cleanup made after discovering testing.CustomEnvironConfig().
Rename parseTag to tagToCollectionAndId
Update tests too
Merge pull request #1190 from mjs/environ-test-config-cleanup

state: cleaner env config generation in EnvironSuite

A small cleanup made after discovering testing.CustomEnvironConfig().

(Review request: http://reviews.vapour.ws/r/500/)
Merge pull request #1197 from johnweldon/0-parseTag-refactor

Rename `parseTag` to `tagToCollectionAndId` for clarity

Minor feedback from previous PR - mechanical change

(Review request: http://reviews.vapour.ws/r/508/)