add a new (optional) .dtsh basepath parameter in the "Stream" enntry

[ricfio]

Hi, as wrote here #22 (comment)

MistServer does generate a small .dtsh file for every VoD file that's been included in MistServer (it will be placed next to the VoD file)

Now suppose that I don't like to save .dtsh files in the same VoD resource folder, or that my VoD files reside in a read-only mounted device... could we add a new optional "dtsh_basepath" parameter in the "Stream" entry to specify where to read/write the .dtsh files for the specific stream source?

The "dtsh_basepath" parameter (default: the same path of the VoD source) could be added after the "Source" field and before "Stop sessions":

Example (current behaviour):

• /vod/vod-resource.mp4
• /vod/vod-resource.mp4.dtsh

Example (with the new configuration param: dtsh_basepath=/opt/mistserver-files/dtsh-folder):

• /vod/vod-resource.mp4
• /opt/mistserver-files/dtsh-folder/vod/vod-resource.mp4.dtsh