TST: Deprecation -> FutureWarning + catch in tests
BUG/TST: fix get_schema + add tests

- adapt signature of get_schema to what it was before (for backwards compatibility), possibility to call function without connection object
- fix get_schema for sqlalchemy mode
- add tests
SQL: revert deprecated tquery/uquery to 0.13 version

As tquery and uquery are deprecated, it is not needed to adapt them to the new sqlalchemy interface + the adapted version changed the signature slightly so it was not fully backwards compatible.
Therefore: put back the old code and removed new implementatation in the classes.
Consequence: the functions are not available for the new sqlalchemy engines, but as they are deprecated this is not needed.
ENH: support pie plot
PERF: optimize Index.delete for dtype=object
TST: clean skipping tests in test_offsets
Merge pull request #7042 from jreback/test_offset

TST: clean skipping tests in test_offsets
Merge pull request #7040 from immerrr/perf-index-delete

PERF: optimize Index.delete for dtype=object
Merge pull request #6976 from sinhrks/pie

ENH: support pie plot in series and dataframe plot
BUG: fix handling of color argument for variety of plotting functions

parallel_coordinates
- fix reordering of class column (from set) causing possible color/class
  mismatch
- deprecated use of argument colors in favor of color
radviz
- fix reordering of class column (from set) causing possible color/class
  mismatch
- added explicit color keyword argument (avoids multiple values 'color' being
  passed to plotting method)
andrews_curves
- added explicit color keyword argument (avoids multiple values 'color' being
  passed to plotting method)
TST: add tests for deprecation warnings from plotting functions

parallel_coordinates/andrews_curves
- added deprecate_kwarg decorator for using frame argument instead of data
- added tests to check that FutureWarning is raised properly
DOC: Reorganize visualization.rst

- add matplotlib to intersphinx
- put random seeds in supress and note
- use versionadded in more places
- link to api on more methods
- title case titles
- reorganize hierarchy

The new hierarchy is

- Basic Plotting (line plots on Frame and Series)
- Other Plots (bar, scatter, etc.)
- Plot formatting

DOC: add ecosystem note to top of visualization.rst

DOC: use cubehelix, not jet

fix line lengths on headers

reorg hierarchy to basic, other, and styling

Change matplotlib url
Merge pull request #7027 from TomAugspurger/visualization-rewrite

DOC: Visualization reorganization
DOC: Add parameter to docstring
ENH: cythonize groupby count
VB: add a vbench for groupby count
BUG: numeric_only must be False for count
CLN: EAFP for count
DOC: add release and v0.14.0.txt notes
Small typo