* Wrap HTML attributes in quotes according to their content. If it contains a double quote use single quotes, otherwise escape with double quotes.
* Add escape_html utility to ensure quote entities are converted identically across Python versions.
Fixes#1260
ref #1689
* set default settigns in settings.py to False for
- LOAD_CONTENT_CACHE
- CACHE_CONTENT
* remove AUTORELOAD_IGNORE_CACHE and add deprecation warning
* update settings.rst to reflect the new default values
* update test_cache to enable caching options
* break out cache into cache.py
* break out cache-tests into test_cache.py
* fix broken cache tests
* replace non existing assert calls with self.assertEqual
* fix path for page caching test (was invalid)
* cleanup test code
* restructure generate_context in Article and Path Generator
* destinguish between valid/invalid files correctly and cache accordingly
* use cPickle if available for increased performance
