(fix #2097) PGF: get fonts from fc-list, use builtin fonts for tests
Don't close figure if context and apply_rcparams are both set. Fixes #2890.
DOC/BUG : fixed sphinx markup

 - issue introduced in #2836
 - closes #2982
Merge pull request #2983 from tacaswell/doc_format_fix

DOC/BUG : fixed sphinx markup
Merge pull request #2914 from astrofrog/fix-plot-directive-rcparams

Don't close figure if context and apply_rcparams are both set.
Allow :context: directive to take 'reset' option. Fixes #2892.
Added What's New entry for :context: reset
Merge pull request #2913 from astrofrog/reset-context-plot-directive

Allow :context: directive to take 'reset' option. Fixes #2892.
small error in install faq
Merge pull request #2829 from pwuertz/fix_2097

(fix #2097) PGF: get fonts from fc-list, use builtin fonts for tests
Merge pull request #2984 from fariza/doc_error_install_faq

small error in install faq
Don't call Py_DECREF on null in _ttconv.cpp

Clang's static checker noted that if PyBytes_FromString returns NULL
(presumably rare) then Py_DECREF gets called on NULL; throw an
exception instead. Also assert that the char* inputs are not NULL,
since the Python API functions don't usually check that.
Initialize offset to zero in FT2Font::make_open_args

Clang warns that it gets a garbage value on Python 2, since
mpl_PyFile_Dup expands to a function call that does not use &offset.
It seems that the value is not used on Python 2 but it doesn't
cost much to silence the warning.
Silence some writable-string warnings

Cast string constants explicitly to (char*) since the
method calls aren't going to modify the strings.
Check the return values of mpl_PyFile_DupClose
Remove dead assignment

The value initially assigned to pix was never used.
Remove dead assignments in _image.cpp
Avoid a null-pointer dereference in _tri.cpp

Found using the clang static analyzer:
if PyArray_ContiguousFromObject returns NULL,
PyArray_NDIM(x) causes a null-pointer dereference.
Initialize the states array with calloc in _macosx.m

To silence a warning about garbage data from the clang
static analyzer. Also check the calloc return value.
Release some unreleased objects in the macosx backend