simpleTV httpTimeshift with catchup tag support
supported tags:
    catchup=""               - catchup type, now supported: 'default', 'append', 'shift', flussonic, flussonic-hls, fs
    catchup-type=""          - same as 'catchup'
    catchup-days=""          - archive depth in days
    catchup-minutes=""       - archive depth in minutes
    catchup-source=""        - alternate address for archive
    catchup-record-source="" - like catchup-source but for record, for example:  catchup-record-source="?utcstart=${start}&utcend=${end}" 
    tvg-rec=""               - some as 'catchup-days'

TODO: flussonic-ts, stalker

supported catchup vars:
   ${start}       - start time in Unix Timestamp
   ${timestamp}   - current time in Unix Timestamp
   ${offset}      - offset in sec
   ${length}      - length in sec
   ${duration}    - same as 'length'   
   ${end}         - end time in Unix Timestamp
