* add pjlink media player component
* retrieve pjlink device name from projector if name isn't specified in configuration
* update .coveragerc
* fix style
* add missing docstrings
* address PR comments from @MartinHjelmare
* fix code style
* use snake case string for source names
* add missing period at the end of comment string
* rewrite method as function
* revert to use source name provided by projector