app: Add support for multiple CRLs.
This changes Kedifa.__init__ and Kedifa.loadCertificate method signatures: they now expect filepaths instead of files with a name attribute.
This also changes the (internal ?) Kedifa.crl property in 2 ways:
- renamed to
crl_list - items are loaded CRLs, and not PEM-encoded CRLs. I did not see the point of re-serialising the CRLs after loading if they are anyway loaded again in
SSLAuth(the only obvious user of this property)