mumble_plugin.h: change plugin magic values in preparation of the MSVS 2013 switch-over.
mumble_plugin.h: change plugin magic values in preparation of the MSVS 2013 switch-over.

Mumble 1.3.0 on Windows will be built with MSVS 2013. That means
that old plugins will no longer load into it (Mumble will crash
if we try), because of C++ ABI differences between MSVS 2010
and MSVS 2013.

To combat this, we switch our plugin magics such that no ABI
mismatches can happen: Old clients will refuse to load new plugins,
and new clients will refuse to load old plugins.

We have a precedent for doing this. See dac82c99 (MSVS 2010 switch-over).

bheart/mumble,Keridos/mumble,mbax/mumble,SuperNascher/mumble,austinliou/mumble,richard227/mumble,Githlar/mumble,unascribed/mumble,SuperNascher/mumble,Lartza/mumble,Natenom/mumble,LuAPi/mumble,ccpgames/mumble,austinliou/mumble,Keridos/mumble,Natenom/mumble,unascribed/mumble,Keridos/mumble,feld/mumble,Natenom/mumble,mbax/mumble,bheart/mumble,ccpgames/mumble,unascribed/mumble,unascribed/mumble,bheart/mumble,niko20010/mumble,mbax/mumble,Natenom/mumble,mbax/mumble,Keridos/mumble,Lartza/mumble,Lartza/mumble,SuperNascher/mumble,niko20010/mumble,LuAPi/mumble,Zopieux/mumble,feld/mumble,Zopieux/mumble,SuperNascher/mumble,ccpgames/mumble,LuAPi/mumble,richard227/mumble,Zopieux/mumble,niko20010/mumble,LuAPi/mumble,bheart/mumble,SuperNascher/mumble,Zopieux/mumble,Keridos/mumble,Natenom/mumble,ccpgames/mumble,niko20010/mumble,Lartza/mumble,Natenom/mumble,feld/mumble,SuperNascher/mumble,Githlar/mumble,niko20010/mumble,LuAPi/mumble,Githlar/mumble,ccpgames/mumble,unascribed/mumble,mbax/mumble,bheart/mumble,ccpgames/mumble,Githlar/mumble,Zopieux/mumble,LuAPi/mumble,Githlar/mumble,ccpgames/mumble,richard227/mumble,Lartza/mumble,Lartza/mumble,LuAPi/mumble,Keridos/mumble,unascribed/mumble,richard227/mumble,niko20010/mumble,mbax/mumble,feld/mumble,ccpgames/mumble,richard227/mumble,richard227/mumble,unascribed/mumble,Githlar/mumble,Lartza/mumble,niko20010/mumble,Githlar/mumble,SuperNascher/mumble,Zopieux/mumble,richard227/mumble,SuperNascher/mumble,Zopieux/mumble,austinliou/mumble,niko20010/mumble,Natenom/mumble,mbax/mumble,Zopieux/mumble,LuAPi/mumble,feld/mumble,Keridos/mumble,austinliou/mumble,mbax/mumble,feld/mumble,austinliou/mumble,Keridos/mumble,Lartza/mumble,Githlar/mumble,austinliou/mumble,LuAPi/mumble,bheart/mumble,feld/mumble,richard227/mumble,bheart/mumble,austinliou/mumble,feld/mumble,unascribed/mumble,bheart/mumble,Natenom/mumble,SuperNascher/mumble,austinliou/mumble