attempted fix for inconsistent debug refcounters on blocks. pinning pieces with outstanding reads in an attempt at fixing inconsitencies seen around that logic as well

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10301 a83610d8-ad2a-0410-a6ab-fc0612d85776
some more connection_queue removals

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10302 a83610d8-ad2a-0410-a6ab-fc0612d85776