Add support to extend commands bpfix and androidmk

Allows our partners to maintain partner-specific fixes in their repos. Converts most of androidmk into a library similar to bpfix. Makes some methods and types public for use by extended versions.

Bug:140727544
Test: Ran unit test cases &&
  ran test conversions with sample
Change-Id: I7e1fbf3a6a7a8bd47334f43fe3eb68cbbd3426c1
diff --git a/androidmk/partner_androidmk/Android.bp b/androidmk/partner_androidmk/Android.bp
new file mode 100644
index 0000000..532116a
--- /dev/null
+++ b/androidmk/partner_androidmk/Android.bp
@@ -0,0 +1,49 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//
+// Sample project for creating an extended androidmk
+//
+
+blueprint_go_binary {
+    name: "partner_androidmk",
+    srcs: [
+        "partner_androidmk/androidmk.go",
+    ],
+    testSrcs: [
+        "partner_androidmk/androidmk_test.go",
+    ],
+    deps: [
+        "androidmk-lib",
+        "partner_bpfix_extensions",
+    ],
+}
+
+blueprint_go_binary {
+    name: "partner_bpfix",
+    srcs: [
+        "partner_bpfix/bpfix.go",
+    ],
+    deps: [
+        "bpfix-cmd",
+        "partner_bpfix_extensions",
+    ],
+}
+
+bootstrap_go_package {
+    name: "partner_bpfix_extensions",
+    pkgPath: "partner/android/bpfix/extensions",
+    srcs: ["fixes/headers.go"],
+    deps: ["bpfix-lib"],
+}