Python3 fixes:

- Use either func_code or __code__ for function object depending on python version.
  Can't use 2to3 because it wants to change other func_code symbols defined in numba
- Change node lineno default from None to -1, since sorting mix of None and int objects doesn't work in python3
Support compilation of lambda functions
Test for #321 (fix in 1fcb4b83d4fdf4b1)
Update #321 for python 2.6
Merge branch 'devel'