rewrite the project as a static site generator

this removes Flask, reworks a number of library methods accordingly, and
adds generators and build commands to process the instance directory
(largely unchanged, except config.py is now config.json) and spit out
files suitable to be served by a web server such as Nginx.

there are probably some rough edges here, but overall this works.

also note, as this is no longer server software on a network, the
license has changed from AGPLv3 to GPLv3, and the "or any later version"
allowance has been removed

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

CONTRIBUTING.md

@@ -3,8 +3,7 @@
 incorporeal-cms is a personal project seeking to implement a simpler, cleaner form of what would
 commonly be called a "CMS". I appreciate any help in making it better.
 
-incorporeal-cms is made available under the GNU Affero General Public License version 3, or any
-later version.
+incorporeal-cms is made available under the GNU General Public License version 3.
 
 ## Opening Issues