Add : The patchlevel with which the module has been built is now exported with the VMG_PERL_PATCHLEVEL constant.
Chg : Version checking macros overhaul.
Fix : 'uvar' magic should only be enabled in maint-5.10 and higher since it's never going to be backported to 5.8.
Fix : Likewise, the copy callback API change should only be enabled in 5.11 and higher.
Fix : Instead of those ackward fake refcount increments in the wizard destructor, flag the wizard with SVf_BREAK and force temps cleanup. This should fix the wizard destruction for all perls, and solves the leak introduced by the previous solution.