Merge pull request #54 from janschulte/develop

merge base64 output encoding
Merge pull request #10 from 52North/develop

Develop
rename exception type 500
some refactoring
prepare metadata property for timeseries data
update documenataion
refactor
add first/last value to timeseries metadata
refactor a bit
formatting
update API doc
prepare Timeseries metadata for reference values
merged
Merge pull request #66 from ridoo/master

merge feature branches to main branch
add category resource
add categorie count to resources
add categorie count to service information
Merge