attempt to fix mingw build

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code/branches/RC_1_0@10293 a83610d8-ad2a-0410-a6ab-fc0612d85776
fix -fvisibility=hidden in makefile

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code/branches/RC_1_0@10294 a83610d8-ad2a-0410-a6ab-fc0612d85776
fix so version in CMakeList.txt

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code/branches/RC_1_0@10295 a83610d8-ad2a-0410-a6ab-fc0612d85776
remove potentially privacy leaking extension (non-anonymous mode). peer-id connection ordering fix in anonymous mode

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code/branches/RC_1_0@10297 a83610d8-ad2a-0410-a6ab-fc0612d85776