BLD: added caching to setup.py - speeds up testing dramatically.

Cythoning results and compiled extension are cached.

This is disabled by default, to enable it uncomment the line
specifying the cache directory at the top of setup.py.

you need to occasionally empty the cache manually, to keep
it from from growing too much.
BLD: added caching to setup.sys - speeds up testing dramatically.

Cythoning results and compiled extension are cached.

This is disabled by default, to enable it uncomment the line
specifying the cache directory at the top of setup.py.

you need to occasionally empty the cache manually, to keep
it from from growing too much.
BUG: 0/0 and nan/0 should equal nan
ENH: make None/NaN different from INF/-INF (GH #1919)
ENH: special option for writing infs in csvs no longer needed
BUG: DateTimeConverter typo calls np._asarray_tuplesafe. TST: a few more test cases for DateTimeConverter.convert
fix sql keywords in columns name bug

the function `pandas.io.sql.write_frame` failed if keywords were
used as column names in a DataFrame. i have added hard brackets
to the column names as generated by the `get_sqlite_schema`
function and created a test case in `test_sql.py`
ENH: add method use_inf_as_null to core.common (GH #1919)
DOC: update docs about null/missing values
DOC: add caveat regarding the use of dicts as arg to read_csv()
DOC: grammer

[ci skip]
BUG: index.format should accept unicode index names
CLN: Move test_console_encode out of wrong test class
TST: unless a file is pure ascii, you must specify an encoding
TST: remove fmt.test_to_string_force_unicode

I think this is the wrong behaviour, and it breaks some
future unicode fixes. the constructor should  should complain
that no encoding was specified when the input is not ascii.
CLN: Move _is_sequence() from pd.frame to pd.common, with other is_*
TST: add test for _is_sequence()
ENH: rework console encoding detection in fmt.print_config
ENH: Add helpers to pd.common: pprint_thing/_encoded(),console_encode()
TST: add test_pprint_thing()
TST: Series repr fails when name is tuple holding non string-type #2051