Added temporary blocks

[lineke]

Through configuration it is now possible to support the following usecases:

• Never block
• Always permanently block after x attempts
• Only temporary blocks after x attemps for a certain duration
• After x temporary blocks the user gets permanently blocked

This code is backwards compatible. Clients don't support the temporary blocks yet.

[ijansch]

merged, although we should actually first try to get the client side changes in, and the json responses.

[ijansch]

or actually I'll wait for those before we merge for compatibility.

[lineke]

I added the JSON responses as well. There is still one todo left and that is to check which response we are using through the parameters we get from the client. I only implemented the JSON responses for the login, not for enrollment. We need to discuss where I can find that in the code.

[lineke]

Several changes to change the response as we discussed. The tiqr library will now always return an array for the response and there could be several response classes if this would change in the next version. The simplesaml module has a response class for fallback to the old plain response.

Todo: the simplesaml module needs to be changed to actually return json and not an array like it does now

[ijansch]

Looks good at first sight, but I'll wait ith merging until the todo you mentioned is also fixed so we don't break the current version when merging

[lineke]

I added the json header support and the enrollment support (with backwards compatibility). Now we can test this with the client changes soon.

[ijansch]

Looks great now, merged!