glvis@3.3: new package (#7166)

* glvis@3.3: new package

* mesa-glu: now provides 'glu' (GL Utility library)

* openglu: add package, provides glu

* [GLVis] Use MakefilePackage as base. Add 'develop' version.

Small tweaks in the makefile arguments.

* [GLVis] Locate the X11, GL and GLU libraries within their respective
prefixes. Set the C compiler in the makefile arguments.

* [GLVis] Fix a bug: the same variable was used for two different things.

* [libx11] Add the libs property

* [OpenGL] Add the libs property

* [OpenGLU] Add the libs property

* [GLVis] Use the libs properties of libx11, opengl, and openglu

var/spack/repos/builtin/packages/libx11/package.py

@@ -44,3 +44,12 @@ class Libx11(AutotoolsPackage):
     depends_on('pkgconfig', type='build')
     depends_on('util-macros', type='build')
     depends_on('perl', type='build')
+
+    @property
+    def libs(self):
+        for dir in ['lib64', 'lib']:
+            libs = find_libraries('libX11', join_path(self.prefix, dir),
+                                  shared=True, recursive=False)
+            if libs:
+                return libs
+        return None