Use modules for pyimport
Add pysym function to modules
Add exports statement, rename pysym to pymember
Define modules as constant on @pyimport
Use pywrap_module for pylab
Remove old pywrap(), rename pywrap_module() to pywrap()
Simpler pattern for determining whether we can use __all__ for exports
Merge pull request #28 from simonster/anon-module

RFC: Use modules for pyimport