e: stop warning about GNU make extension
e: stop warning about GNU make extension

We know wildcard is an extension of GNU make and we don't need to be
remembered every single compilation. Remove noise like below:

doc/Makefile.am:42: warning: wildcard img/*.*: non-POSIX variable name
doc/Makefile.am:42: (probably a GNU make extension)



SVN revision: 78723

FlorentRevest/Enlightenment,FlorentRevest/Enlightenment,rvandegrift/e,rvandegrift/e,FlorentRevest/Enlightenment,tasn/enlightenment,tizenorg/platform.upstream.enlightenment,tasn/enlightenment,rvandegrift/e,tasn/enlightenment,tizenorg/platform.upstream.enlightenment,tizenorg/platform.upstream.enlightenment