Configure on OSX 10.1

[jpff]

First problem is that it defines CPP="gcc -E -no-cpp-precomp"
but the C compiler is called cc and so this fails.  For now I have
edited this to read CPP="cc -E -no-cpp-precomp" but I suspect it out
to be something like CPP=`echo $CC -E -no-cpp-precomp`

I also got the following warning, and so am reporting as requested.
No idea what it is about

checking net/if.h presence... yes
configure: WARNING: net/if.h: present but cannot be compiled
configure: WARNING: net/if.h: check for missing prerequisite headers?
configure: WARNING: net/if.h: proceeding with the preprocessor's result
configure: WARNING:     ## ------------------------------------ ##
configure: WARNING:     ## Report this to address@hidden ##
configure: WARNING:     ## ------------------------------------ ##
checking for net/if.h... yes

==John ffitch