New rtc dump analyzing tool in Python

tools/py_event_log_analyzer/README

+This file describes how to set up and use the RTP log analyzer.
+
+Run the tool as follows:
+
+    python rtp_analyzer.py <rtc event log>
+
+where <rtc event log> is a recorded RTC event log, which is stored in
+protobuf format. Such logs are generated in multiple ways, e.g. by
+Chrome through the chrome://webrtc-internals page.
+
+The script has been tested to work in python versions 3.4.1 and 2.7.6,
+but should work in all python versions for which there is a version
+of the dependencies.
+
+Dependencies
+------------
+
+The analyzer script needs *numpy* (http://www.numpy.org/) and
+*matplotlib* (http://matplotlib.org/).
+
+When using python 2, the package *future*
+(https://pypi.python.org/pypi/future) is needed. This package can be
+installed through pip, (https://docs.python.org/2.7/installing/).

[kwiberg-webrtc, 2016/05/25 12:42:41]

Hmm. You use very few things from this library---just builtins.input and
builtins.range if I'm not missing anything. Can you do without it?

[aleloi2, 2016/05/30 14:57:55]

Yes, I changed bultins.range to just 'range', which should be fine because the
only resevant difference is memory consumption. We already keep all of the data
in memory. I replaced the builtins.input dependency with a custom input function
in latest misc.py

+
+A version of Protocol Buffers is needed as well. One is distributed
+along with WebRTC in `thirdparty/protobuf/python`. This tool also
+needs a file `rtc_event_log_pb2.py` which is automatically generated
+from `webrtc/call/rtc_event_log.proto` and placed in
+`out/<TARGET>/pyproto/webrtc/call/` with every WebRTC compilation. To
+use it, WebRTC needs to be compiled before using this tool.
+
+An alternative to compiling WebRTC is to install your own version of
+Protocol Buffers and `protoc`, the Protocol Buffer compiler.
+
+If you use your own version of protobuf, generate the python file in
+this folder with
+
+   protoc -I $WEBRTC_ROOT/webrtc/call $WEBRTC_ROOT/webrtc/call/rtc_event_log.proto --python-out ./
+