fe4df311-ls185

LinuxServer Changes:

Add perl-json-xs package.

tvheadend Changes:

Fix htsstr_argsplit (treat quotes inside an argument correctly)

There seemed to be a flaw in the splitting logic when it comes to quotes, e.g.:
--output="filename" should be one argument, but htsstr_argsplit treated it as
['--output=', '"filename"] which I think is wrong.

I fixed this and added two tests for this scenario.