Merge pull request #100 from bmcfee/master

Updated docs and readme
Add a tiny bit of padding to make sure librosa.load(..., duration=..) returns the right number of frames after resampling
Merge pull request #124 from bmcfee/master

merging master into develop
merge of resampling length fixup and resampling multiple channels
make import builtins work on py2.7
Merge branch 'develop' of https://github.com/bmcfee/librosa into develop
fix for reading zero-length files; reverse mis-fix of import builtins
adding function cache, re: #80
added joblib and decorator to requirements
better no-cache implementation
decorator module is broken
enabled caching in all submodules
disabling caching on rapid-fire functions
removed unnecessary cache calls
disable cache for docbuilding
no caching when the input has a call method
cannot cache agglomerative either
updated unit tests to skip caching
added transparent decorator recipe
added documentation for cache. Closes #80.