Fixes magfest-archive/panels#103: Adds custom jinja environment that …

…lets plugins override templates (magfest#2884)

* Fixes magfest-archive/panels#103: Moves form logic to "baseform.html" so other plugins can override blocks

* Uses custom jinja environment and loader to do template inheritance from multiple plugins

* Changes name from PluginEnvironment to more accurate & descriptive MultiPathEnvironment

* Sorts the set of template files used as cache key, so it's deterministic

* Adds missing import statement

* Adds empty unit tests file for new jinja environment and loaders

* Attempting to use thread local variables to store template stack

* This is, I believe, the most efficient way of implementing the multi-path template strategy

* Removes unused imports

* Adds unit tests for jinja.MultiPathEnvironment and jinja.AbsolutePathLoader

* Responding to Eli's review comments

Final Magstock 2016 Release

Merge pull request magfest#1140 from magfest/change_badge_shift

fixed badge update code to work on non-preassigned badges

Merge pull request magfest#1046 from magfest/update-docs

updating docs

don't require emergency contact number

comment out kiosk mode for now for attendees. HACK

fix extra "staffers" link

Simplified a little by pulling some stuff outside the "if"

Merge pull request magfest#304 from magfest/new_gfx

add magfest 8.5 themed graphics

final post-con tweaks, I think

fixed staffer summary