Fix the environment so Ruby-Augeas finds the Augeas package information.
This has not been pushed upstream as it is Solaris-specific.

--- ruby-augeas-0.5.0/ext/augeas/extconf.rb.orig	2016-04-29 14:31:16.171732595 -0600
+++ ruby-augeas-0.5.0/ext/augeas/extconf.rb	2016-04-29 14:31:39.159244851 -0600
@@ -23,12 +23,13 @@
 
 extension_name = '_augeas'
 
-unless pkg_config("augeas")
-    raise "augeas-devel not installed"
+$CFLAGS += " -I/usr/include/libxml2"
+unless have_library("augeas")
+    raise "libaugeas not installed"
 end
 
-unless pkg_config("libxml-2.0")
-    raise "libxml2-devel not installed"
+unless have_library("xml2")
+    raise "libxml2 not installed"
 end
 
 create_makefile(extension_name)