Add new config options for rpi IR in bootcfg.txt

[FauthD]

Hi Seahawk,
as promised in the portal here comes the pull-request that adds the pwm sender for IR.
Also added a way to add arbitrary lines to the usercfg.txt.
And examples to groupvar/all.

PS:
My first pull-request with github. In the job I use Bitbucket and Gitkraken.
And let me thank you for bringing me into the world of Ansible. I learned about it as I saw yavdr-ansible and wondered what the hell is Ansible. Meanwhile I use it a lot.

A much better way compared to the old yavdr ISO files.

Thanks, Dieter Fauth