Provide a way to escape # in an ini file

For the Stillberg dataset, we want to set the key:

ACDD_METADATA_LINK = https://www.envidat.ch/#/metadata/meteo-stillberg

Since # is the character used for comments, we only get "https://www.envidat.ch/" as metadata link in the generated data files. The most logical way to fix it would be to be able to escape #, for example giving the link as https://www.envidat.ch/#/metadata/meteo-stillberg