[PATCH] mod_smtpd configure fixes

[Garrett Rooney <ro...@electricjellyfish.net>]

On my Ubuntu linux box, the Apache2 apxs is installed as 'apxs2', and 
the httpd binary is installed in the SBINDIR, not BINDIR, and is not 
named httpd, so the current configure script can't find it.  Here's an 
updated version that makes two changes, first it lets you specify a full 
path to the apxs binary, second it makes the search for the apache 
binary check both the SBINDIR and BINDIR directories, and makes it query 
apxs for the actual program name.

A log message and patch follows.

-garrett

* configure.ac
   (CHECK_VERSION): try the SBINDIR directory in addition to the BINDIR,
    and query apxs for the httpd program name instead of hardcoding
    httpd.
   (APACHE_DIR): interpret an argument that points to a file as the full
    path to apxs.