Allow buildconf to find the config.m4 files in the correct order. This

Allow buildconf to find the config.m4 files in the correct order.  This
allows the decisions made in one config.m4 file to be based on decisions
made in previous config.m4 files.  For example, the config.m4 in the
generators config.m4 can choose the correc cgi module based on which MPM
is chosen.

To do this, we find all filenames config*.m4, and then we re-order the
filename so that it looks like:  *config.m4/path/to/file.  Once all files
are in this format, we sort the files, and then re-arrange the file names
again to put them in the correct order.  There may be better ways to do
this, but I couldn't find a portable way to call sort so that this would
work.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@87526 13f79535-47bb-0310-9956-ffa450edef68