Gpxity

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* utility for testing installation in a docker container
* version number is not in the source anymore, setup.py creates version.py

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* gpxdo ls --long is no longer ignored
* explicitly enforce utf-8 when reading or writing .gpx files
* improve setup.py
* require gpxpy 1.2.0

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* Backend has a new arg "timeout"
* README has a link to readthedocs
* Auth: added an example
* Backend.sync_from is gone, there are now Track.merge() and Backend.merge()
* diverse fixes for gpxdo
* Track.what is now always in internal format
* Simplify specific backend code by moving more code into the general Backend class
* Track.dirty is gone, there now is Track.rewrite()
* Backend: renamed save() to add()
* Track.identifier is new, to be used by gpxdo
* Track.length is the track length
* gpxdo ls has many more options, including --sort
* gpxdo rm has a new option --dry-run

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* New backend GPSIES for www.gpsies.com
* New: Command line utility "gpxdo" exposing commands for listing, copying,
merging, removing, editing, fixing, comparing
* New class BackendDiff
* Backend: rename copy_all_from to sync_from and add parameters
* hide class Authenticate from public API
* Define assumption about points having to be ordered by time
* Do not use slow GPX.get_time_bounds()
* Track.last_time now is a property
* MMT: Map Track.keywords to MMT tags
* Track.keywords now returns them sorted
* MMT: login only once per backend instance
* Make list(Track) sortable (by title)
* New: Track.adjust_time()
* Track: Improve __str__ and __repr__
* Backend can now be used as an iterable
* New class BackendDiff
* MMT now supports life tracking
* New generator Track.segments()
* Simplify usage of auth.conf
* fix illegal XML generated by gpxy for GPX 1.1
* New: Backend.match implements client-side filtering
* New: BackendException
* New: Map values for "what" between different backends
* New: Backend.legal_whats shows the values for "what" supported by a backend

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* a first example
* simplify authentication
* simplify Backend API
* len(backend) is the number of tracks
* Allow backend[x] and x in backend
* hide Backend.tracks, directly add needed methods to Backend
* MMT: Download track sometimes did not download the entire track
* bin/test and bin/coverage now accept test method names (without `test_` prefix)
* Directory: removes dead links without raising an exception
* Track.description never returns None
* Track: Parsing illegal GPX XML now prints a more helpful error message
* Track.clone() first does load_full
* Track(gpx=gpx) now handles keywords correctly
* Backend.save() now accepts ident=str
* Directory tries not to use illegal file names for symlinks

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* Added Changelog