412712 - HttpClient does not send the terminal chunk after partial writes.

HttpGenerator._header and HttpGenerator._buffer may be null when
the content is written after a partial write.
In this case, the terminal chunk was not prepared, and therefore never
written.

The fix simply creates a HttpGenerator._header to prepare the terminal
chunk, so that it will be written.
412750 HttpClient close expired connections fix
413684 - Trailing slash shows JSP source

+ Adding testcase to replicate issue.
413684 - Trailing slash shows JSP source

Fixed alias checkers.   Non existent directory does check for none existence.  Prefix and Suffix check look for none empty/trivial prefix/suffixes
Merge remote-tracking branch 'origin/jetty-7' into jetty-8