mac build really does not like finding extra stuff in the PATH
or in /usr/local/bin
as this is prone to happen with macport/fink/etc..
or somethings just due to some other 'ported to mac' pre-canned
binaries..
for instance one has found a python3 in /usr/local/bin
which confused configure to believe it was ok to use
'system python', which break on mac.

This patch sanitize PATH during ./autogen.sh, when running
in a LODE environment.
it leave only LODE_HOME/opt/bin:/usr/bin:/bin:/usr/sbin:/sbin  and optionally
the path where git is located if that is not /usr/bin
(it is quite common depending on how one installed git, to haev it in /usr/local/git/bin
for instance)

This is strictly a 'nanny' patch.. but it should not impact anyone
that is not ( on Mac and using LODE ).

Change-Id: I865047cfeb102ecb22777a1f7fb7cbdd374448aa
Reviewed-on: https://gerrit.libreoffice.org/16222Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Norbert Thiebaud <nthiebaud@gmail.com>