py: Put number parsing code together in parsenum.c.
Add basic super() test.
Add arbitrary precision integer support.

Some functionality is still missing (eg and, or, bit shift), and some
things are buggy (eg subtract).
Merge branch 'master' of github.com:micropython/micropython
Add Configurable LFN support to FatFS
Merge pull request #316 from iabdalkader/fatfs_lfn

Add Configurable LFN support to FatFS
stm: Add USART enum for pyboard skin labels.
stm: Make pendsv_nlr_jump work when debugging is enabled.

Stack layout is different when -g used, so need to handle the pendsv
jump differently.  Addresses Issue #315.