The include file for C routines is generated by configure,
in a way that should be very general and robust. Beware:
you need to re-run configure to regenerate include/c_defs.h
git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@3423 c92efa57-630b-4861-b058-cf58834340f0
giannozz