UPDATE: add HACK to allow scrobbling

Added fictional duration to songs as a HACK to enable scrobbling

* scrobbling doesn't work with the current XBMC core player unless the
  'duration' field of the song info is set to a positive number prior to
  starting the song (even though the song duration will be correct in the player)
* with no 'duration' (or 0 or -1), last.fm is notified of  the song playing but
  never receives the final scrobble notification to add it to the history
* BUG: the HACK does cause the core player to see/display an incorrect total
  song time (although the progress/duration bar is visually correct)

NOTE: scrobbles may be cached until the Pandora script is halted and then submitted en mass

NOTE: (see URLref: http://www.last.fm/api/scrobbling) for scrobble info
UPDATE: remove excess 'pithos' code

* Remove excess 'pithos' code that has nothing to do with the pandora module that we're using
* pithos.pandora code is current to repo [2b35f36b91 on 2013-12-19]

* NOTE: 'pithos' repo @ https://github.com/pithos/pithos
UPDATE: minor code, meta-info, and UI cleanup
UPDATE: add option to sort stations; emphasize QuickMix/Shuffle station

* added option to sort station names in station list
* changed QuickMix name to differentiate it from regular stations
UPDATE: add optional automatic playback of previous station

* Added optional automatic playback of previously playing station
* UI settings updated
* Code changes modelled after code by @robweber (see https://github.com/robweber/script.xbmc.pandorajson.git)
CHANGE: some DRY code cleanup
FIX: remote STOP now stops

* A STOP signalled by a remote now stops playback, instead of skipping to the next song
* Code influenced by @robweber (see https://github.com/robweber/script.xbmc.pandorajson.git)
CHANGE: minor comment updates and whitespace changes
FIX: add proxy functionality back into code

* recent 'pithos' update removed proxy functionality from Pandora()
* added proxy code back in via a class wrapper (My_Pandora())
BUGFIX: repair the regression causing low/medium quality songs to be unplayable

* Changed to the old xbmc.player syntax specifying the player type (eg, now
  using "xbmc.Player( xbmc.PLAYER_CORE_MPLAYER ).play( url, item )")
* NOTE: prior change to "xbmc.Player().play( url, item )" was suggested by the
  XBMC team, but causes .mp4 files to be unplayable with codec errors

* Thanks to Nikolas Garofil for taking the time to help me find the proxy and quality issues
CHANGE: some comment additions & cleanup
UPDATE: version update