update dune-gfe.m4 from a recent run of 'duneproject'

[[Imported from SVN: r9985]]

m4/dune-gfe.m4

-AC_DEFUN([DUNE_GFE_CHECKS],[
-#  AC_REQUIRE([DUNE_IPOPT])
-])
+dnl -*- autoconf -*-
+# Macros needed to find dune-gfe and dependent libraries.  They are called by
+# the macros in ${top_src_dir}/dependencies.m4, which is generated by
+# "dunecontrol autogen"
+
+# Additional checks needed to build dune-gfe
+# This macro should be invoked by every module which depends on dune-gfe, as
+# well as by dune-gfe itself
+AC_DEFUN([DUNE_GFE_CHECKS],[])
 
-AC_DEFUN([DUNE_GFE_CHECK_MODULE],[
-  DUNE_CHECK_MODULES([dune-gfe], [gfe/rotation.hh])
+# Additional checks needed to find dune-gfe
+# This macro should be invoked by every module which depends on dune-gfe, but
+# not by dune-gfe itself
+AC_DEFUN([DUNE_GFE_CHECK_MODULE],
+[
+  DUNE_CHECK_MODULES([dune-gfe],[gfe/rotation.hh])
 ])