[Opendnssec-develop] shared autoconf macros

[Jakob Schlyter]

I've started to collect some shared autoconf macros (like ldns,  
libxml2, strict, ...) and collected them in one file so we don't check  
for stuff differently all over the place.

I'm about to move all shared autoconf/configure stuff into this and  
please help if you find anything missing. after update trunk/m4/ 
acinclude.m4, just do a 'make install' in trunk/m4 to update all local  
copies (and don't forget to commit them as well).

	jakob