cleaned up include tree
AosShellChannel now contains a pointer to a BaseAsynchronousChannel instead of a AosIOCHannel.Fixed an issue with AosIOStreams as well as AosShellStreams regarding multiple reading/writing from/to channels.
Major overhaul to the I/O functionality:
The SequentialStremMultiplexer (SSM) has been replaced by AosIOStream.The AosIOStream class acts like a BaseSequentialStream but consists of multiple AosIOChannels.Each AosIOChannel again implements a BaseAsynchronousChannel and thus is a derived class of BaseSequentialStream as well....
Modified aos_unittest.h/.c files to prevent unnecessary includes.
Major overhaul to AMiRo-OS version 2.0.0