Final test and misc fixes: - add basic coverage analysis script - gdbstub only build one of libgdb_user/softmmu - don't break BSD gdb by advertising AUXV feature - add MAINTAINERS section for policy docs - add more verbiage to -blockdev/-drive usage in docs - update hexagon toolchain - explicitly invoke iotests with python for BSDs benefit - use system python on NetBSD - add some tests for the new KVM Xen guest support