fix proxy redirect (http status 302) response
fixes http://mantis.tokeek.de/view.php?id=517

The url given in bug report uses a gzip input stream which causes the HTTPClient.writeto() throw an IOException due to incomplete input stream. This in turn prevents the 302 reponse to the client browser. 
By limiting to serve target content just on httpstatus=200 will proxy the header reponse and client browsers redirect settings can be honored.
update to SLF4J 1.7.9
fix div by 0 in hello
Caused by: java.lang.ArithmeticException: / by zero
	at hello.respond(hello.java:159)
crawling of multi-page pdfs with artificial post part on smb or ftp
shares is not possible with the disabled setting; this is not temporary
disabled until a better solution is on the hand.
Merge branch 'master' of git@gitorious.org:yacy/rc1.git