bURL-0.4

Support of orco - Org Column add-on for Thunderbird:

• Extract mid: links by default.
• Allow to add custom URI schemes through -scheme CLI options.
• CLI options to specify emacsclient arguments or alternative
  executable: -emacsarg and -emacsclient.
• Allow to change list of extension IDs in manifest
  through -chrome-extension and -firefox-extension options.
• burl.linkSet RPC method to get list of URIs matching
  passed list of prefix variants and the -disable-link-set
  CLI option to disable it.

New CLI options mostly may be used multiple times,
to reset default values specify empty argument ''.