refactor server command

[elmiko]

currently the server is nominally useful but it only works for a single must-gather and doesn't provide much. it would be nice to refactor the server mode so that a user could specify a url that the server would pull the must-gather from. it would then use the tar unpacking method to create the static page to serve. this will allow the server to be useful on a wide level in remote deployment scenarios,

the url might be specified through a path parameter, or perhaps as a form that could allow uploading.