BF: Don't add properties from base classes if they have been re-defined/overwritten in a sub class

See merge request fsl/fsleyes/props!58

re-defined/overwritten in a sub class

RF: Don't override bounds default when minval/maxval are set.

See merge request fsl/fsleyes/props!56

set, but min/max are, set default to them

MNT: mock modules to make docs build

See merge request fsl/fsleyes/props!54

Various enhancements

See merge request fsl/fsleyes/props!52

specified

arguments

arguments.  New alias "Props", because even "HasProps" is too short. Adjust
some logging calls to use delayed string construction.

CI: change image for pages job

See merge request fsl/fsleyes/props!50

Mnt/matplotlib

See merge request fsl/fsleyes/props!48