Refresh API

Analog functions of the former refexport_t are now public for the client
to access.
R_Init

Refactoring <> re.Init -> R_Init
R_RegisterModel

Refactoring <> re.RegisterModel -> R_RegisterModel
R_RegisterModel and R_RegisterSkin

Some serious refactoring
Draw_FindPic

Refactoring <> re.RegisterPic -> Draw_FindPic
Serious refresh refactoring

Draw_Pic, R_SetSky, Draw_GetPicSize, R_RenderFrame, R_EndRegistration
are now fully glued to the client
More serious refactoring

R_Shutdown, R_SetPalette, Draw_Fill, Draw_StretchRaw, Draw_Char,
Draw_StretchPic, R_BeginFrame, GLimp_EndFrame, Draw_TileClear,
Draw_FadeScreen have been glued to the client
First big jump into the blue

All references to refexport_t have been taken out ...
Client refactoring

Cmd_AddCommand and Cmd_RemoveCommand are called directly by the client
and not through refimport_t function pointers
It's all set

Apparently this is it!, there are absolutely no ref exports/imports
between client and refresh, it's all tight code between them ... :)
So far so good

Making big changes :)
Code cleanup

Some stuff being reordered
Cleanup

Some stuff being removed finally ...
VID_ declarations

VID_ declarations are known by the refresh.
Serious cleanup and some formatting

Refresh imports and exports are now officially deleted ...