dropping autoconf dependency on imake

[kodis at mail630.gsfc.nasa.gov]

On Wed, Mar 28, 2007 at 12:21:14AM +0200, Bernardo Innocenti wrote:
> Why does [autoconf] need imake?  Can we get rid of it?

>From the autoconf info file:

    The following macros check for operating system services or
    capabilities.

     - Macro: AC_PATH_X
	 Try to locate the X Window System include files and
	 libraries.  If the user gave the command line options
	 `--x-includes=DIR' and `--x-libraries=DIR', use those
	 directories.  If either or both were not given, get the
	 missing values by running `xmkmf' on a trivial `Imakefile'
	 and examining the `Makefile' that it produces.  If that fails
	 (such as if `xmkmf' is not present), look for the files in
	 several directories where they often reside.  If either
	 method is successful, set the shell variables `x_includes'
	 and `x_libraries' to their locations, unless they are in
	 directories the compiler searches by default.