dbghelp: When using a regular expression on a file name, interpret '*' as any string (.* in regexp form).

EXT_swap_control redefines glXSwapIntervalSGI() as glXSwapIntervalEXT() on the
current drawable (if any), and glXSwapIntervalEXT() supports disabling vsync.

The swapchain was the last place using IParent, so this allows us to kill
IParent completely.

insertBefore() is able to work on nodes from different documents, so on 
adding child or sibling it's possible that libxml2 switches doc pointer 
for a node, we need to update refcounts to cover that case.