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/cblas/package.py

@@ -0,0 +1,35 @@
+from spack import *
+import os
+
+class Cblas(Package):
+    """The BLAS (Basic Linear Algebra Subprograms) are routines that
+       provide standard building blocks for performing basic vector and
+       matrix operations."""
+
+    homepage = "http://www.netlib.org/blas/_cblas/"
+
+    # tarball has no version, but on the date below, this MD5 was correct.
+    version('2015-06-06', '1e8830f622d2112239a4a8a83b84209a',
+            url='http://www.netlib.org/blas/blast-forum/cblas.tgz')
+
+    depends_on('blas')
+    parallel = False
+
+    def patch(self):
+        mf = FileFilter('Makefile.in')
+
+        mf.filter('^BLLIB =.*', 'BLLIB = %s/libblas.a' % self.spec['blas'].prefix.lib)
+        mf.filter('^CC =.*', 'CC = cc')
+        mf.filter('^FC =.*', 'FC = f90')
+
+
+    def install(self, spec, prefix):
+        make('all')
+        mkdirp(prefix.lib)
+        mkdirp(prefix.include)
+
+        # Rename the generated lib file to libcblas.a
+        install('./lib/cblas_LINUX.a', '%s/libcblas.a' % prefix.lib)
+        install('./include/cblas.h','%s' % prefix.include)
+        install('./include/cblas_f77.h','%s' % prefix.include)
+