installation: add Flask-Admin
OpenAIRE: fix issue with persistent identifier miniting
OpenAIRE: fix mailto link in contact page
OpenAIRE: fix problem with unicode filepath
BibFormat: add display of software documentation
OpenAIRE: fix unicode error
admin: adds Flask-Admin support
pidstore: add initial administration interface

* Adds initial administration interface to PID store.
pidstore: fix undefined variable issue
OpenAIRE: fix unicode decoding in notify task