Improving test/demo server performance by adding excludes and moving demo_utils.coffee out of demo/ directory

Changed hemlib.py to take an "excludes" parameter, and also changed how the test() route function works to only pull in the coffee source of the requested demo
removing test_utils from demo/
Merged functionality of testserver.py into demoserver.py

Created a separate /demo URL route in addition to the /test route
Removing test_utils.coffee and merging into testutils

Also adding small check so that make_glyph_test() can accept a single glyphspec or multiple glyphspecs
Removing demo_utils.coffee

Everything just uses testutils now
Renaming some variables in the Demo and Test templates