Create basic OpenRC service

[kapsh]

Support is optional, therefore init/conf files will be prepared for packagers while building but not installed.

Closes #102

[kapsh]

This will create service and configuration files under install/openrc, packager can install them after build is finished as /etc/conf.d/xow and /etc/init.d/xow respectively. Flexible enough and shouldn't break existing builds this way.

[kakra]

Is it possible to load openrc services as part of udev plug&play? There's a pull requests which converts the systemd service to be triggered by device plug in udev. This seems to solve a compatibility issue / race condition, and I wonder if openrc should do the same.

[kapsh]

@kakra should be as simple as RUN+="rc-service xow start/stop in add/remove actions of udev rule.

Looking at https://github.com/medusalix/xow/pull/116, relevant parts could be added but commented out, this way users will have choice between plug&pray (suggest uncommenting in docs) and always enabled service (rc-update add xow, and this implementation will restart xow if it exits without dongle or when another error has happened).

[mrturcot]

@kakra should be as simple as RUN+="rc-service xow start/stop in add/remove actions of udev rule.

Looking at #116, relevant parts could be added but commented out, this way users will have choice between plug&pray (suggest uncommenting in docs) and always enabled service (rc-update add xow, and this implementation will restart xow if it exits without dongle or when another error has happened).

Sorry if this a newb question but how am I supposed to get xow working in Gentoo?