Metacat

Added a new URL protocol handler class for the metacat protocol. This
class will replace the current MetacatURL class in a much simpler and
extensible manner. See the documentation for java.net.URLConnection and
java.net.URL for details.

this class allows the parsing of xml data sent by a replication server to assertain document info about a remote document.

added functionality to allow the replication servlet to assertain and insert user and group info into the local database. started implementation of insert replication handler (it is commented out in this commit)

fixed compatibility problem by overloading the write method. Jivka's new parameter (Reader acl) is now defaulted to null if it is not explicitly declared.

added interface to handle a new "acl" parameter bringing the text of a xml access file for a given metadata document
the "acl" parameter is optional and should be sent on INSERT or UPDATE action.

new class for parsing ACL XML file and loading acl data into metacat db

added delete functionality

added support for server_location in the xml_revisions table.

removed inadvertent comments

removed dependence on a server code in the accession number of each document. the file's resident server is now located in xml_documents.server_location.