Release_Notes_4.0.txt

Release 4.0 of pySlip has the following changes:

1. Uses wxPython 4.0.

2. Uses python 3.6+.

2. A more streamlined way to define tile sources.

3. Additional tile source modules:
     Blue Marble tiles          (blue_marble.py)
     Stamen Toner tiles         (stamen_toner.py)
     Stamen Transport tiles     (stamen_transport.py)
     Stamen Watercolor tiles    (stamen_watercolor.py)

4. A method of changing the tile source for an existing pySlip instance.
   See the API documentation for more details.  The examples/pyslip_demo.py
   program has been extended to exercise this new functionality.

5. A mechanism to update tiles sourced from a server.  See the API
   documentation for details on managing this feature.

6. Merged in a fix from fivitti to address issue #61: OSM tiles not behaving.
   This fix allows user code to set a user agent string for a tile source.
   This has NOT been tested by me since I can't run wxpython on MacOS.

The built in GMT tiles are not at the same zoom level as the internet tiles.
This may change in the future.