added graphviz and dependencies

var/spack/packages/ghostscript/package.py

@@ -0,0 +1,17 @@
+from spack import *
+
+class Ghostscript(Package):
+    """an interpreter for the PostScript language and for PDF. """
+    homepage = "http://ghostscript.com/"
+    url      = "http://downloads.ghostscript.com/public/ghostscript-9.16.tar.gz"
+
+    version('9.16', '829319325bbdb83f5c81379a8f86f38f')
+
+    parallel = False
+
+    def install(self, spec, prefix):
+        configure("--prefix=%s" %prefix, "--enable-shared")
+
+        make()
+        make("install")
+

var/spack/packages/graphviz/package.py

@@ -0,0 +1,21 @@
+from spack import *
+
+class Graphviz(Package):
+    """Graph Visualization Software"""
+    homepage = "http://www.graphviz.org"
+    url      = "http://www.graphviz.org/pub/graphviz/stable/SOURCES/graphviz-2.38.0.tar.gz"
+
+    version('2.38.0', '5b6a829b2ac94efcd5fa3c223ed6d3ae')
+
+    parallel = False
+
+    depends_on("swig")
+    depends_on("python")
+    depends_on("ghostscript")
+
+    def install(self, spec, prefix):
+        configure("--prefix=%s" %prefix)
+
+        make()
+        make("install")
+

var/spack/packages/pkg-config/package.py

@@ -0,0 +1,17 @@
+from spack import *
+
+class PkgConfig(Package):
+    """pkg-config is a helper tool used when compiling applications and libraries"""
+    homepage = "http://www.freedesktop.org/wiki/Software/pkg-config/"
+    url      = "http://pkgconfig.freedesktop.org/releases/pkg-config-0.28.tar.gz"
+
+    version('0.28', 'aa3c86e67551adc3ac865160e34a2a0d')
+
+    parallel = False
+
+    def install(self, spec, prefix):
+        configure("--prefix=%s" %prefix, "--enable-shared")
+
+        make()
+        make("install")
+