PY2to3: Made imports relative, changed print statements to function calls, updated the use of range to reflect python 3 changes, and updated use of map to reflect python 3 changes.

Conflicts:
	quantecon/__init__.py
	quantecon/quadsums.py
Py2to3: Iterators don't allow the .next() method, changed it to reflect the new syntax.
PY2to3: Updated the examples folder.  Verified changes, but mostly followed 2to3 -w filename.py
py2to3: One last fix in lqramsey_ar1, import from directory not quantecon.
py2to3: One last fix in odu_plot_densities.py, import from directory not quantecon.
PY2TO3: Changed quad.py to be python 3 compatible.
PY2to3: quad.py is now python 2 and python 3 compatible and passes tests in both versions.
CLN: removed stub test_asset_pricing.py file.

Will reinstate when we write real tests
py2to3: made examples/wb_download.py work on py2 and py3
py2to3: confirmed that all solutions notebooks work on python 3
BUG: fixed bug in jv

scipy.optimize.fmin_slsqp doesn't work the same in python 2 and 3

I switched to using the COBYLA method and it works on both versions.

Also there was an ImportError in odu_plot_densities
Merge pull request #33 from jstac/compat

Compat
deleted unnecessary file descriptor_eg.py
MERGE: Bring in the python 2 to 3 compatibility fixes.