port to mac os.
fixed spell error in README
replace hardcode with macro
add example: low level shader api
Merge branch 'master' of ssh://oa.ejoy.com/ejoy2d
add comment
Merge branch 'master' into public
typo
move the mac os file to separate folder.
Revert "move the mac os file to separate folder."

This reverts commit b84c9b950ef782aa07be3ba530ffda9d7cc44955.
change the xinux name to posix.
Merge branch 'master' of https://github.com/cloudwu/ejoy2d

Conflicts:
	Makefile
readlink("/proc/self/exe", tmp, bufsz); canot get the path in mac os. I don’t know how to get a portable solution. In some shells, getenv(“_”) works.
add other platform code back.
Merge pull request #11 from Tsiannian/master

port to mac os.
Link lua52.dll in windows
Merge branch 'master' of github.com:cloudwu/ejoy2d into public
label example
fix Issue #14
set global OS in lua