Added the core package.
Added the TransportWithCookies class to preserve Bugzilla's session
cookies. Also added the Apache XML-RPC client library.
Implemented the connection methods for BugzillaImpl, an implementation
of the Bugzilla SPI class.
Added the BugzillaTransportException to wrap the underlying XML-RPC
exceptions.
Added the login and logout methods.
Merge pull request #3 from TomRK1089/xmlrpc_bugzilla_base

XML-RPC core transport functionality added.