Add gstmix to configure options
Update to EAPI 5 + gtk-doc changes

Bump to EAPI 5
Remove doc USE flag
Take out configure option.
Update to EAPI 5 + gtk-doc changes

Bump to EAPI 5
Remove doc USE flag
Take out configure option.
Update to EAPI 5 + gtk-doc changes

Bump to EAPI 5
Remove doc USE flag
Take out configure option.
Update to EAPI 5 + gtk-doc changes + udev depend fix

Bump to EAPI 5
Remove doc USE flag
Take out configure option.
Depend on virtual/udev
Update to EAPI 5 + gtk-doc changes

Bump to EAPI 5
Remove doc USE flag
Take out configure option.