Rework of my pull request #18:
* Implement "go to next" buttons in pyfile UI
* Improve filter on main UI to persist over page reloads
* Hide totals table footer if hiding any rows, as values will be inaccurate
* Implement live filtering of index table rows
* Upgrade to jQuery 1.11.1
* Respond to pull request #18 comments
* Do not try to jump to line if we can't find a matching target.
Merged ned/coveragepy into default
Address comments from pull request 34 (https://bitbucket.org/ned/coveragepy/pull-request/34/rework-of-my-pull-request-18/diff):

* Remove fixed header and header buttons in file details page.
* Add dynamically summing footer values.
Merged ned/coveragepy into default
* Remove "source indicator" CSS from removed feature.
* Merge changes from head.
Improve performance of coverage under PyPy.

An explanation is in order:

should_trace_cache is a strictly growing key, which is to say once a key is in it, it never changes.

Further, the keys used to access it are generally constant, given sufficient context. That is to say, at any given point _trace() is called, a Sufficient Smart Compiler (tm) is able to know the key. This is because the key is determined by the physical source code line, and that's obviously invariant with the call site.

This property of a dict with immutable keys, combined call-site-constant keys is a match for PyPy's module dict, which is optimized for such workloads.

This gives a 20% benefit on the workload described at https://bitbucket.org/pypy/pypy/issue/1871/10x-slower-than-cpython-under-coverage

I have not benchmarked on a wider array of programs yet.

--HG--
branch : alex_gaynor/improve-performance-of-coverage-under-py-1411425050845
Use the capitalized name. If we even keep this singleton stuff...
"concurrency" is a better name that "coroutine"

--HG--
rename : tests/test_coroutine.py => tests/test_concurrency.py
Some error checking and more tests for concurrency control.
Add docs for --concurrency
Document stuff for 4.0a1
Make these proper unittest asserts
Skip a test on Windows for now.
Fix the sphinx extension.
Update version and docs for 4.0a1
Build windows kits on 3.4 also
Fix the release date