TST:  Don't segfault when categorical groupby differs in length from series, GH3011
BUG: add length check on categorical grouper, GH3011
TST: add bounds-checking preamble to groupby_X cython code
ENH: add bounds-checking preamble to groupby_X cython code
TST: Enforce grouper=f() result has len(labels) == len(data) GH3035
BUG: Enforce grouper=f() result has len(labels) == len(data) GH3035
DOC: Update v0.11.0.txt
ENH: improve performance of df.to_csv GH3054
ENH: to_csv using masking to simplify dtype processing
ENH: more perf tweaks in df.to_csv
PERF: cythonized parts of to_csv for increased perf
PERF: more cython tweaks
PERF: cythonize improved python version
PERF: cythonized parts of to_csv for increased perf
PERF: more speedups
ENH: add chunksize parameter to DataFrame.to_csv to enable constant memory usage
     by writing in chunks
CLN: move repeated cast out of loop
CLN: make guard more defensive
REF: add com._ndarray_to_native_types
REF: apply native type conv to ix, cols before write_csv