remove pch.hpp

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@10048 a83610d8-ad2a-0410-a6ab-fc0612d85776
initialize pad files to priority 0 by default

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@10049 a83610d8-ad2a-0410-a6ab-fc0612d85776