Renamed BdfReader methods, added convenience methods.

briar-api/src/org/briarproject/api/data/BdfReader.java

briar-core/src/org/briarproject/data/BdfReaderImpl.java

...r-core/src/org/briarproject/forum/ForumListValidator.java

...e/src/org/briarproject/forum/ForumSharingManagerImpl.java

briar-core/src/org/briarproject/invitation/Connector.java

...briarproject/properties/TransportPropertyManagerImpl.java

...g/briarproject/properties/TransportPropertyValidator.java

briar-tests/src/org/briarproject/data/BdfReaderImplTest.java