added .sce extension support and clarification in description

[unknovs]

added .sce extension support as defined in ETSI TS 102 918 clause 6.2.1.
Added clarification in description that XAdES signature verification is done. (CAdES is not supported).
Made PR in edockit to support .sce as well edgarsj/edockit#1

[edgarsj]

1. Thanks for the .sce support.
2. CAdEs:
   1. Not sure about whether I want to make text in edocviewer.app more technical as it is at this point. Might do a separate more technical information page apart from the main window.
   2. Will look into if I can do the CAdES support quickly (example documents welcome to my email, if there's anything you can share) see issue

So, I'll probably integrate your sce file extension support fix separately from the text improvements and figure the rest out.

[unknovs]

Skaties pats, man profesionālais kretīnisms, ir lietas ko gribas saukt vārdos :)

[unknovs]

1. Thanks for the .sce support.

   2. CAdEs:

      1. Not sure about whether I want to make text in edocviewer.app more technical as it is at this point. Might do a separate more technical information page apart from the main window.
      2. Will look into if I can do the CAdES support quickly (example documents welcome to my email, if there's anything you can share) see issue

So, I'll probably integrate your sce file extension support fix separately from the text improvements and figure the rest out.

P.S. CAdES supportu nevajag ieviest, ASIC-E + CAdES ir ļoti liels retums. Pamatā CAdES izmanto dažādiem sistēmas parakstiem un ļoti reti tie ir asice konteineros.