update java checks & warnings with upstream

Change-Id: If85ec95a519740469eeca1f549b8c0ef975977fe
Signed-off-by: Dennis Rassmann <showp1984@gmail.com>

make those infos warnings

Change-Id: I05859b873a25bb755fea75e67e840b4592ad3622
Signed-off-by: Dennis Rassmann <showp1984@gmail.com>

add hint for usage of java 6

Change-Id: I5e4f3a1f1192caf8f41142dc2829092701b8cba5
Signed-off-by: Dennis Rassmann <showp1984@gmail.com>

Fix merge error

Change-Id: I8639212bb8e185bd68241190f0caf09753df7de5
Signed-off-by: Dennis Rassmann <showp1984@gmail.com>