Logger cause many gc.

[auxor]

Cling is a great project for dlna, and have enough for debugging. However, there is no way to disable log in release build. Logger code cause so much string allocating and gc. The following are some gc log in android.

01-19 10:28:16.398 1473 1487 I art : WaitForGcToComplete blocked for 100.878ms for cause Alloc
01-19 10:28:16.399 1473 4673 I art : WaitForGcToComplete blocked for 101.861ms for cause Alloc.

I have try to use proguard to remove log code. See https://www.guardsquare.com/en/proguard/manual/examples#logging.

The logger code is removed，but the string allocating in logger calling is kept.