Fix #1466 : Performance warning: Send Buffer Watermark
Add external ip alert handler to core
Ensure status message is reset after leaving Error state

Also clean up comments in core.py
Add TorrentStorageMovedEvent for #637
Fix #2006 : Display error when moving storage location fails

Adds handler for storage_moved_failed_alert and then sets the
torrent to Error state and pauses it.
Fixed small bug in path_combo_chooser

The delete-text event was triggered when setting the text in the text entry.
The completion popup was then displayed when it shouldn't. Fixed by blocking
the signal while setting the text.
Flake8'd gtkui/path_combo_chooser
Fix #2409 : Console Non-interactive curses ImportError
Fix crash if translations are missing
Fix empty message for certain tracker status errors

By design alert.msg will be empty if the error code is '-1' so use
a.e.message() to get the message as fallback. It was not used at
replacement because when error code is not '-1' then a.e.message()
will also include the error code, which we do not want.
Fixed glade missing signal warning in path_combo_chooser
add comment to tracker_error_alert handler
Include small upstream bencode fix and flake8 file
Fix common.free_space to handle path is None
GTKUI: Ensure None value from problem config is empty string for set_text
Change get_default_download_dir to use expanduser as fallback
[#2082] Validate ip address for listen_interface entry

This ensures that only ip addresses are accepted for
listen_interface as libtorrent cannot accept interface
names (eth0) and will cause unexpected results for user.
[#2417] Add time_since_download and time_since_upload to torrent status
Add torrent bandwidth priority to core
Remove unneeded old 'public' option code