Hew hooks API. Second try

[Khimenko Victor]

No more hacks in mod_so. Instead all modules unregister hooks before unload.
Also some slightly non portable defines (still ANSI compliant AFAIK) moved
in few separate defines in top of ap_hook.h and new ap_hook_define_global/
ap_hook_define_realize to make hooks more usable in multifiles client modules.

EAPI-2-EAPIk-4-2.1b9-SNAP.patch2.gz