reorganize octave_config_info again * build-env-features.sh: Don't include ENABLE_ items in the output. * toplev.cc (find_config_info): New static function. (Foctave_config_info): Put Octave configuration info in the main struct. Put the build system features and build environment info in substructures. Allow searching of all elements by keyword. * __have_feature__.m, doc/interpreter/testfun.txi: Fix name of build features substructure element. * geometryimages.m, interpimages.m, plotimages.m, sparseimages.m, splineimages.m: Use __have_feature__ to check for OSMESA.

--- a/scripts/testfun/__have_feature__.m	Mon Feb 08 17:34:12 2016 -0500
+++ b/scripts/testfun/__have_feature__.m	Mon Feb 08 23:14:56 2016 -0500
@@ -22,7 +22,7 @@
 ## @end deftypefn
 
 function retval = __have_feature__ (feature)
-  features = octave_config_info ("features");
+  features = octave_config_info ("build_features");
   if (iscellstr (feature))
     retval = (all (isfield (features, feature))
               && cellfun (@(x) features.(x), feature));