worked on the ISBN scanner (#8):
- only accepts ISBN10 and ISBN13
- can handle display rotation after scan (ISBN number + format will be stored in tmp SharedPreferences)
- user gets message if ISBN number is not known in DoeLibS
- during connect to the API (check if ISBN is available) a ProgressDialog will be show
made loading consistent (use now ProgressDialog for login too)
added Exceptions for different HttpStatus codes so we can difference better between errors
Merge pull request #3 from creydr/isbn-scanner_development

isbn-scanner_development
show now the users firstname and lastname in the navigationbar instead of the email
Merge pull request #4 from creydr/isbn-scanner_development

isbn-scanner_development
Merge pull request #28 from creydr/master

ISBN scanner  #8