liblogd: LogBuffer classes and their support, LogReaderList and
LogReaderThread
logd: liblogd + the socket code that connects liblogd to liblog and
therefore the world.
The goal here is to test liblogd offline of the socket connections or
the device.
Also, convert libaudit.c -> libaudit.cpp and modernize a bit.
Test: build
Change-Id: If5adf5e775a251d9a703c0583be0988f48017347
