New, cleaner package repository structure.

Package repositories now look like this:

    top-level-dir/
        repo.yaml
        packages/
            libelf/
                package.py
            mpich/
                package.py
            ...

This leaves room at the top level for additional metadata, source,
per-repo configs, indexes, etc., and it makes it easy to see that
something is a spack repo (just look for repo.yaml and packages).

var/spack/repos/builtin/packages/SAMRAI/no-tool-build.patch

@@ -0,0 +1,20 @@
+--- SAMRAI/Makefile.in	2013-05-31 11:04:32.000000000 -0700
++++ SAMRAI/Makefile.in.notools	2014-05-30 10:31:15.135979900 -0700
+@@ -8,7 +8,7 @@
+ ##
+ #########################################################################
+ 
+-default: library tools
++default: library
+ 
+ SAMRAI  = @top_srcdir@
+ SUBDIR  = .
+@@ -135,7 +135,7 @@
+ 	done
+ 	$(MAKE) archive_remove_obj_names
+ 
+-install: library tools
++install: library
+ 	$(INSTALL) -d -m 755 $(INSTDIR)/config
+ 	$(INSTALL) -d -m 755 $(INSTDIR)/lib
+ 	$(INSTALL) -d -m 755 $(INSTDIR)/bin

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

@@ -0,0 +1,53 @@
+from spack import *
+
+class Samrai(Package):
+    """SAMRAI (Structured Adaptive Mesh Refinement Application Infrastructure)
+       is an object-oriented C++ software library enables exploration of numerical,
+       algorithmic, parallel computing, and software issues associated with applying
+       structured adaptive mesh refinement (SAMR) technology in large-scale parallel
+       application development.
+    """
+    homepage = "https://computation.llnl.gov/project/SAMRAI/"
+    url      = "https://computation.llnl.gov/project/SAMRAI/download/SAMRAI-v3.9.1.tar.gz"
+    list_url = homepage
+
+    version('3.9.1',      '232d04d0c995f5abf20d94350befd0b2')
+    version('3.7.3',      '12d574eacadf8c9a70f1bb4cd1a69df6')
+    version('3.7.2',      'f6a716f171c9fdbf3cb12f71fa6e2737')
+    version('3.6.3-beta', 'ef0510bf2893042daedaca434e5ec6ce')
+    version('3.5.2-beta', 'd072d9d681eeb9ada15ce91bea784274')
+    version('3.5.0-beta', '1ad18a319fc573e12e2b1fbb6f6b0a19')
+    version('3.4.1-beta', '00814cbee2cb76bf8302aff56bbb385b')
+    version('3.3.3-beta', '1db3241d3e1cab913dc310d736c34388')
+    version('3.3.2-beta', 'e598a085dab979498fcb6c110c4dd26c')
+    version('2.4.4',      '04fb048ed0efe7c531ac10c81cc5f6ac')
+
+    depends_on("mpi")
+    depends_on("zlib")
+    depends_on("hdf5")
+    depends_on("boost")
+
+    # don't build tools with gcc
+    patch('no-tool-build.patch', when='%gcc')
+
+    # TODO: currently hard-coded to use openmpi - be careful!
+    def install(self, spec, prefix):
+        mpi = next(m for m in ('openmpi', 'mpich', 'mvapich')
+                   if m in spec)
+
+        configure(
+            "--prefix=%s" % prefix,
+            "--with-CXX=%s" % spec[mpi].prefix.bin + "/mpic++",
+            "--with-CC=%s" % spec[mpi].prefix.bin + "/mpicc",
+            "--with-hdf5=%s" % spec['hdf5'].prefix,
+            "--with-boost=%s" % spec['boost'].prefix,
+            "--with-zlib=%s" % spec['zlib'].prefix,
+            "--without-blas",
+            "--without-lapack",
+            "--with-hypre=no",
+            "--with-petsc=no",
+            "--enable-opt",
+            "--disable-debug")
+
+        make()
+        make("install")