Core: Get rid of function prototypes in ActionReplay.cpp

Also marked said functions static
Core: Get rid of calls to mem_fn in thread instantiations

These are not necessary for the same behavior.
Merge pull request #765 from lioncash/memfn

Core: Get rid of calls to mem_fn in thread instantiations
Merge pull request #763 from lioncash/ar

Core: Get rid of function prototypes in ActionReplay.cpp
Core: Get rid of C-style struct typedefs
Merge pull request #766 from lioncash/structs

Core: Get rid of C-style struct typedefs
Merge branch 'master' of https://github.com/dolphin-emu/dolphin into VR-Hydra
X-Ray and Thermal Visors mostly working.