Revert "pyximport: parse distutils config files (except local setup.cfg)"

This reverts commit 813ff05a80cef908704488e660fa07d49feb8a92.

This was an accidentally applied twice.
use all distutils config files

It is very astonishing to a user, that pyximport uses a different
set of config files from the underlying distutils.
remove unreachable code
use context manager to close file, and more explicit variable name
move first part of the logic into a wrapping function

this should help to decouple from the filesystem and heuristic in
filenames
add a directive to disable SwitchTransform

SwitchTransform is unable to detect all cases of duplicate values, which
result in errors at compile time in the generated code.
make _save annotation a io-less method
fix accidental removal of a line
clearup unused arguments and close P tags
split _save_annotation on multiple function

will allow refactor of the cython magic not to parse temporary files
and not to leak css into IPython notebooks
add unique class name to avoid conflic

in particular tings like 'code' are conflicting when embeding the page
forgotten self
thou no need space for css selector
Let cython.inline return all defined variables by default.
Refine analysis of undeclared symbols in cython.inline.

Previously cython.inline didn't correctly handle variables
declared in nested scopes (such as function declarations).
rename "switchcase_transform" to "use_switch"
better logic for C compile failure support in runtests.py
Merge pull request #287 from gandalf013/switch_transform

add a directive to disable SwitchTransform
Document use_switch directive.
Fail test when expected C compiler error not encountered.