[Omake] autoconf-style configure-time options

[Erick Tryzelaar]

Whats the best way to specify configure options via the command line? As 
far as I can tell, .STATIC blocks are run before omake processes the 
command line. I believe this means that you can't, say, "omake 
ENABLE_VSNPRINTF=0" on the command line to skip testing if vsnprintf 
exists. Is there any way to do this? I'm trying to figure out how to do 
cross compiling, and I think we'd need something like this in order to 
do it.

Also, is there any way to use a virtual mount so that you can have one 
directory for one configuration, and another for a different config? 
It'd make sense to not have to completely recompile if you wanted to 
test between a coupld different architectures.