Fix typo
Python prefers not to use camelCase but camel_case
Misc. improvements on jsonbackend

- set the ProjectDTO name on the __init__ method itself
- use [] instead of list() to create empty lists
- use the with operator to open files (so they are automatically
  closed)
- instead of going through all properties, just query the ones
  you are interested in and set the value to the project with
  setattr()