Fixed link to filesystem module.
Fixed link for <file-stream> in closing streams section.
Fixed link for <streams> in locking streams section.
Fixed link to make(<byte-string-stream>)
Fixed link for superclass of <byte-vector>
Fixed superclass links for end-of-stream-error and file-error.
Fixed link for <position-type> in value of stream-position.
Fixed link to superclass <object>.
Fixed a bunch of <object> reference that didn't include a link.
Merge pull request #618 from wvdschel/master

Fixed most of the problems reported in issue #608