Add underscore build tests to sauce.
Tweak test filters for backbone and underscore.
Add `_.bind`, `_.partial`, `_.partialRight`, & `_.curry` tests for function `length`.
Minor style tweaks and simplify travis.yml.
Fixed memory leak with debounce/throttle arguments and context
Merge pull request #389 from jayphelps/leaky-pipes

Fixed memory leak with debounce/throttle arguments and context.
Push delay back to see if it helps timing tests in travis/sauce.
Add failing test case for current `_.debounce` patch.
Fix failing `_.debounce` test.
Add a mix of arguments to `_.throttle` tests.
Tweak pull_request detection in saucelabs.js.
Clear `timeoutId` if `func` is called in `_.debounce`.
Add `count` check now that we clear `timeoutId` properly.
Fix typos and rebuild docs & builds.
Ensure recursive `_.throttle` calls still work.
Update builds & docs.
Update qunit-clib to avoid issues with non-writable `context.clearTimeout`.
Set `loader` to `none` by default in test.html and add default values to perf.html too.
Move the QUnit.config.hidepassed setting up.
Optimize `_.omit` for large arrays by leveraging `_.difference` which has optimizations for large arrays.