Setcache

As per #4. Add a setcache feature for keeping a cache hot.

I wrote some tests, and your test suite passes for me except for one test that fails on your master branch for me anyway.


```
ERROR: test_remember_stats_all_urls (fancy_tests.tests.test_views.TestViews)
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Traceback (most recent call last):
  File "/Users/brett/dev/django-fancy-cache/fancy_tests/tests/test_views.py", line 131, in test_remember_stats_all_urls
    match, = find_urls('/anything')
ValueError: need more than 0 values to unpack

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```