[RFA 1/2] do not use python<version> subdir when including Python .h file

[Joel Brobecker]

> gdb/ChangeLog:
> 
> 	* configure.ac: Remove fallback behavior for building
> 	against Python.  Remove tweaking of Python include path.
> 	Add PYTHON_CPPFLAGS and PYTHON_LIBS substitution.
> 	(AC_TRY_LIBPYTHON):  Adjust program used in linking test.
> 	If link is successful, set PYTHON_CPPFLAGS and PYTHON_LIBS.
> 	Always restore CPPFLAGS and LIBS after linking test.
> 	* configure: Regenerated.
> 	* Makefile.in (INTERNAL_CPPFLAGS): Add @PYTHON_CPPFLAGS@.
> 	(INSTALLED_LIBS, CLIBS): Add @PYTHON_LIBS@.
> 	* python/python-internal.h: Adjust includes of Python .h files.

Patch checked in, after confirming that the build works both
in and out of tree...

-- 
Joel