Added ZeroDivisionError to float division.
Implement __aeabi_f2d and __aeabi_d2f
showbc: Dump YIELD_FROM.
Merge remote-tracking branch 'upstream/master'
stmhal: USB CDC and MSC device work together.
Merge branch 'master' of github.com:micropython/micropython
stmhal: Tidy up USB device configuration.  Make it use less RAM.
sthmal: Remove obsolete files.
stmhal: Tidy up USB CDC+MSC device some more.
stmhal: Add PYBv10 config; add RNG support.
Fixed broken math functions that return bool and added some more.
stmhal: Add os module with a few basic functions.
stmhal: Add time module with sleep function.
Added exception hierarchy except for OSError and UnicodeError (requires arguments). Comment out the errors that aren't needed if memory becomes an issue.
stmhal: Add servo driver.
objgenerator: Keep exception stack within generator object, like value stack.

This is required to properly handle exceptions across yields.
objgenerator: Implement throwing exceptions out of generator.
objgenerator: Implement .throw() method to throw exceptions into generator.
Fixed modulo operator on ints and mp ints to agree with python. Added intdivmod.c and tests/basics/modulo.py.
Merge pull request #358 from pfalcon/gen-exc-stack

objgenerator: Implement exception handling for generators