Code layout cleanup

- Fwd declare where possible
- List .h first in the .cpp to verify proper includes
- Remove hacky -internal.h file and move testBitInRange to a new component

Change-Id: I442248c4b32738c6c2af250f45d4c8822c862e08
diff --git a/modules/input/evdev/BitUtils.h b/modules/input/evdev/BitUtils.h
new file mode 100644
index 0000000..1aa1f6a
--- /dev/null
+++ b/modules/input/evdev/BitUtils.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#ifndef ANDROID_BIT_UTILS_H_
+#define ANDROID_BIT_UTILS_H_
+
+#include <cstdint>
+
+namespace android {
+
+/** Test whether any bits in the interval [start, end) are set in the array. */
+bool testBitInRange(const uint8_t arr[], size_t start, size_t end);
+
+}  // namespace android
+
+#endif  // ANDROID_BIT_UTILS_H_