fix cpu core query via cpuid
fix UNIX64 and WIN64: use ecx as input param
add exception handler,  the AMD cpu must be single core if it do not support HTT
Merge branch 'master' of https://github.com/cisco/openh264 into core_number_detect_fix
check cpuid max level before use cpuid.4
protect code if cpuid.4 return eax as zero
win64: Use rsp instead of esp

Using esp works by coincidence as long as the stack pointer is
within the first 4 GB of the address space - which seems to work
as long as the test binary is built with /dynamicbase:no, but breaks
if this option is removed.
Merge pull request #122 from volvet/core_number_detect_fix

Core number detect fix
Merge pull request #131 from mstorsjo/win64-asm

win64: Use rsp instead of esp