winedos: Move VGA_SetGraphicMode() up a bit and make it static. VGA_GetModeInfoList() is unused so remove it.

dbghelp: Improve speed of our hashtable implementation by remembering the last element added to every bucket.

wintrust: Check for the presence of required members of WINTRUST_CERT_INFO rather than requiring callers to be compiled with the same SDK version.

wintrust: Check for the presence of required members of WINTRUST_BLOB_INFO rather than requiring callers to be compiled with the same SDK version.