Ssterm

* Add compatibility for both Python 2 and 3.
* Add setuptools Python packaging.

* Refactor codebase.
* Add support for hexadecimal input mode.
* Add support for piped standard input.
* Fix handling of removed serial port.
* Simplify CLI options with output mode and input mode options.
* Add unit tests for input and output processors.
* Relicense under MIT license.

* Add support for higher baudrates.
* Add support for arbitrary baudrates via BOTHER.
* Clean up codebase some more.

* Switched to gnu_getopt to allow command-line options after serial port device argument.
* Refactored codebase.

* Fixed escape character bug. Switched escape character from Ctrl-[ to the more unique Ctrl-], which does not serve as the escape code for many other special keys and cause ssterm to quit on them like Ctrl-[ did. Thanks to zzazang for discovering this bug.
* Modified formatting of split hexadecimal/ASCII representation mode to conform to "hexdump -C" canonical split output.

* Added support for split hexadecimal/ASCII representation mode.
* Added controlling terminal reset on program quit.
* Fixed non-blocking read bug.