stm: Clean up main.c; disable libgcc by default.

f2d and d2f functions from libgcc does not work correctly, most likely
due to the ABI being incorrect.  libgcc disabled for now.
Merge pull request #204 from dhylands/master

Fix malformed makeqstrdata generated file when using python 2.7
py: Implement break and continue byte codes, and add tests.

Also fixes a bug in the for-in-range optimiser.

I hope to remove break and continue byte codes in the future and just
use jump (if possible).
Merge branch 'master' of github.com:micropython/micropython
py: Remove implicit conversion of float to int in mp_obj_get_int().

Addresses Issue #199.
Fix support for STM32F4DISCOVERY
Merge branch 'fix-stm-discovery' of github.com:dhylands/micropython into dhylands-fix-stm-discovery

Conflicts:
	stm/main.c
Second stage of qstr revamp: uPy str object can be qstr or not.
Add Generic Feature Macros to mpconfigport

* Add some generic feature macros to mpconfigport
* Move pin and port definitions from usrsw.c to mpconfigport
Remove Underscore from Macro Names
file.readline(): Use mp_obj_str_get_data() and fix off-by-one error on EOF.
Fix Feature Macro Prefix
Implement octal and hex escapes in strings.
stm: Fix USART3 init.  Small edits to Makefile and other things.
Merge branch 'master' of github.com:micropython/micropython
Merge pull request #206 from iabdalkader/master

Add Generic Feature Macros to mpconfigport
Merge pull request #208 from pfalcon/string-escapes

Implement octal and hex escapes in strings.
Merge branch 'master' of github.com:micropython/micropython
Fix 1 warning and 1 bug.
py: Initialise loaded_module map in rt_init.

STM port crashes without this re-init.  There should not be any state in
the core py/ code that relies on pre-initialised data.