A check for python binary that was originally introduced by commit
183e869 is needed because python is used for a couple of preprocessors
(doxygen-link.py and resolve-asciidoc-refs.py) and therefore it is
impossible to build docs without python.
While it is right to check for python, the check was both wrong and
excessive. Instead of just checking for python binary, it checked for
various versions of python and set a few variables that are not needed
here. More to say, the absense of python binary was not treated as
being fatal like it should.
Fix both problems by using AC_CHECK_PROG for python, terminating the
build in the same way as with doxygen absense. Also, remove the
m4/ax_python.m4 which is no longer needed.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
60ac492058