plugin.api.http_session: Add a resolve_url method.
plugins.filmon_us: Update to use http.resolve_url().
utils: Deprecate many functions that have been replaced or are not needed.

The following functions are no longer needed:

- swfverify - Use swfVfy in the RTMPStream's params instead

The following functions have been replaced:

- res_json   = plugin.api.http.json
- res_xml    = plugin.api.http.xml
- urlget     = plugin.api.http.get
- urlopen    = plugin.api.http.get
- urlresolve = plugin.api.http.resolve_url