dtype costumization on sql read_table (#8926)

testing dtypes parameter

dtypes defaults to None

dtype type checking and docstrings

dtype exception checking

sphinx dtypes corrections

if/else to or simplification

informative exception of errouneous SQLAlchemy subclassing

type checking

basic documentation of the dtypes feature

issue number

correct test position

issue correction

SQLite dtype configuration

Testing Legagy SQLite with dtype configuration

changed the position of a dtype check

assert_raise

assert_raise

return user specified dtype, not SQL_TYPE

test cleanup

better docstrings

better docstrings

docs and test refactoring

Do not test on MySQL legacy

dtypes->dtype

dtypes->dtype

assert->assertTrue

Type test in mysql

correct mysql test type

reverting unintended change
Merge pull request #8926 from tiagoantao/master

ENH: dtype costumization on to_sql (GH8778)
BUG: Fixed ValueError raised by cummin/cummax when datetime64 Series contains NaT. (:issue:`8965`)
COMPAT: infer_dtype not handling categoricals (GH8974)
Merge pull request #8975 from jreback/infer

COMPAT: infer_dtype not handling categoricals (GH8974)
TST: tests for lib.max_len_string_array
COMPAT: unicode for same
Merge pull request #8978 from jreback/unicode

TST/COMPAT: tests and compat for unicode for lib.max_len_string_array
Updating tests file Cleaning up
BUG: StataWriter uses incorrect string length

Fixes bug where StataWriter always writes strings with
a size of 244.

closes #8969
Merge pull request #8977 from bashtage/stata-writer-string-length

BUG: StataWriter uses incorrect string length
Merge branch 'cummin-NaT' of https://github.com/unutbu/pandas into unutbu-cummin-NaT

Conflicts:
	doc/source/whatsnew/v0.15.2.txt