Kien

* FIX: `regex` validator will always match the full string
(replaced `re.match` with `re.fullmatch`)

* FEATURE: Add "--log-level" commandline parameter.
* FEATURE: Add "--log-filename-by-process" commandline parameter.
* FIX: Improve various details of SIGHUP (disconnect/connect) handling.

* FEATURE: Manage connections on different interfaces with a single startup process
(spawning forked processes for each interface).
* FEATURE: Add support for writing and remove a PID file.
* FEATURE: Allow configuration of baudrate.

* FIX: Force inclusion of package metadata.

* FEATURE: The new `--tty` option accepts a device and will setup a proper terminal on it.
When it’s used in conjunction with the `--reconnect-on-hangup` flag it can
also be used for USB devices that would terminate after the `SIGHUP` process
signal that is emitted, after a physical USB connection has been severed.

* FEATURE: Command keywords can be aliased from now on. See the `keyword` function.
* FEATURE: `to_enum` transform now accepts a static map of enum to alias values.
Combined with the new `keyword` function this allows for easy
command aliases.