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/lmdb/package.py

@@ -0,0 +1,39 @@
+import os
+from spack import *
+
+class Lmdb(Package):
+    """Read-only mirror of official repo on openldap.org. Issues and
+    pull requests here are ignored. Use OpenLDAP ITS for issues.
+    http://www.openldap.org/software/repo.html"""
+
+
+    homepage = "http://www.openldap.org/software/repo.html"
+    url      = "https://github.com/LMDB/lmdb/archive/LMDB_0.9.16.tar.gz"
+
+    version('0.9.16', '0de89730b8f3f5711c2b3a4ba517b648')
+
+    def install(self, spec, prefix):
+        os.chdir('libraries/liblmdb')
+
+        make()
+
+        mkdirp(prefix.bin)
+        mkdirp(prefix + '/man/man1')
+        mkdirp(prefix.lib)
+        mkdirp(prefix.include)
+
+        bins = ['mdb_stat', 'mdb_copy', 'mdb_dump', 'mdb_load']
+        for f in bins:
+            install(f, prefix.bin)
+
+        mans = ['mdb_stat.1', 'mdb_copy.1', 'mdb_dump.1', 'mdb_load.1']
+        for f in mans:
+            install(f, prefix + '/man/man1')
+
+        libs = ['liblmdb.a', 'liblmdb.so']
+        for f in libs:
+            install(f, prefix.lib)
+
+        includes = ['lmdb.h']
+        for f in includes:
+            install(f, prefix.include)