Use CMake for libmng package (#14747)

* Convert libmng to use CMake rather than autoconf

The autoconf script failed to recognize the intel compiler; it was
harwired to use gcc.

* Simplify cmake logic and remove unused variant

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

@@ -6,16 +6,17 @@
 from spack import *
 
 
-class Libmng(AutotoolsPackage):
-    """libmng -THE reference library for reading, displaying, writing
+class Libmng(CMakePackage):
+    """THE reference library for reading, displaying, writing
        and examining Multiple-Image Network Graphics.  MNG is the animation
-       extension to the popular PNG image-format."""
+       extension to the popular PNG image format."""
     homepage = "http://sourceforge.net/projects/libmng/"
     url      = "http://downloads.sourceforge.net/project/libmng/libmng-devel/2.0.3/libmng-2.0.3.tar.gz"
 
     version('2.0.3', sha256='cf112a1fb02f5b1c0fce5cab11ea8243852c139e669c44014125874b14b7dfaa')
     version('2.0.2', sha256='4908797bb3541fb5cd8fffbe0b1513ed163509f2a4d57a78b26a96f8d1dd05a2')
 
+    depends_on("gzip")
     depends_on("jpeg")
     depends_on("zlib")
     depends_on("lcms")
@@ -25,11 +26,6 @@ def patch(self):
         filter_file(r'^(\#include \<jpeglib\.h\>)',
                     '#include<stdio.h>\n\\1', 'libmng_types.h')
 
-    @run_before('configure')
-    def clean_configure_directory(self):
-        """Without this, configure crashes with:
-
-            configure: error: source directory already configured;
-            run "make distclean" there first
-        """
-        make('distclean')
+    def cmake_args(self):
+        return ['-DWITH_LCMS2:BOOL=ON',
+                '-DWITH_LCMS1:BOOL=OFF']