Move paths of all deck slides to match new class structure
Strip tag namespacing from all Advanced deck slides

Simplify the tag naming used in building decks by chapter name by
keeping with only chapter name. This follows the pattern established
in the Foundations (now Intermediate) deck chapters.
Reverse merge to bring up-to-date with master
Merge pull request #106 from github/decks-restructure

Remove three-section deck content tag namespacing for simpler referencing