deprecate most of cache_status type (use session stats instead)

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10443 a83610d8-ad2a-0410-a6ab-fc0612d85776
transition fenced job histogram to session stats gauges. deprecate it from cache_status

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10444 a83610d8-ad2a-0410-a6ab-fc0612d85776
some more fixes to cache_status

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10445 a83610d8-ad2a-0410-a6ab-fc0612d85776
fix stats_alert with recent changes to stats

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10446 a83610d8-ad2a-0410-a6ab-fc0612d85776
finally rename policy to peer_list

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10447 a83610d8-ad2a-0410-a6ab-fc0612d85776