AsyncHttpServer: sendFile enhancements

Change-Id: I9cece9a29b60a8ced57bfa1eab8ecb31362720fe
AsyncServer.stop is now synchronous.
TODO/Feature: Add asynchronous Future version.
At current, stop() is only used during unit tests anyways.

Change-Id: I34a00f723078f9b4df1b44cf8722fa3ebb9007e1
Expose the ResponseCacheMiddleware DiskLruCache.

Change-Id: I2ff2ed8349562a5027c108fb8729a32ee433c0a7
Merge branch 'master' of https://github.com/koush/AndroidAsync

# By Koushik Dutta
# Via Koushik Dutta
* 'master' of https://github.com/koush/AndroidAsync:
  Expose the ResponseCacheMiddleware DiskLruCache.
  AsyncServer.stop is now synchronous. TODO/Feature: Add asynchronous Future version. At current, stop() is only used during unit tests anyways.
  AsyncHttpServer: sendFile enhancements

Conflicts:
	AndroidAsync/src/com/koushikdutta/async/AsyncServer.java