Code cleanup for core files
[GTKUI] Strip whitespace in the interface entry box
Log errors for invalid interface values
Use int function to cast proxy type
Disable SSL listen port
Remove duplicate i2p_proxy entry
[GTKUI] Reorganise layout of tab items and add Tracker tab

 * Changed layout of Status, Details and Options tabs.
 * Moved the Tracker translations to ui.common.
 * Created a new Trackers tab.
 * Added State to progressbar.
 * Translate State in piecesbar.
[GTKUI] Move Piece colour chooser below checkbox
[GTKUI] Remove icons from Tabs
[GTKUI] Change tabs from top to left side
[GTKUI] Tidyup Preferences Dialog

 * Remove unnessary page headers to save space
 * Reordered pages to be lightly grouped
 * Other changes to utilise space better
 * Fixed the plugin info panel collapsing on startup
[GTKUI] Convert the appindicator option into a radio button
[GTKUI] Move 'Add Dialog' prefs to Download tab

Also includes more tweaks to layout for consistency and creating space.
Refactor Torrent _get_pieces_info method

Code is now easier to read and should be a bit faster
Flake8 rencode

Fixes a function declared twice and a few indentation issues
No need to use get_status in Torrent class
Use list comprehension in get_file_progress

Should be slightly quicker with large numbers of files.

Also moved socket import to the top as it will always be imported.
[#2493] [GTKUI] Fix TypeError if active workspace is None
Merge pull request #15 from deluge-torrent/develop

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