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elf: add basic checks for proper binary type
Merge pull request #1 from atgreen/runtime

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elf: add check for moxie arch
record entry point
encapsulate CPU state within machine class
move CPU state init to CPU class constructor
sandbox: wire up initial PC
elf code movement
sandbox.h: implement read mem directly
sandbox: mark addressRange methods virtual
runtime: add "ret" to mmap. update comments.
runtime/make: build test1.o separately
update README
runtime: make test1 more complex (triggering creation of .data, .bss)
convert README to markdown
more README updates
more readme
more readme