FELIX-1955 - configure keystore/truststore types:

- allow the type of keystore/truststore to be configured, for example, to
  use PKCS12 store files;
- added two new configuration options `org.apache.felix.https.keystore.type`
  and `org.apache.felix.https.truststore.type` to define what type of store
  is to be expected.



git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1540723 13f79535-47bb-0310-9956-ffa450edef68