ENH: Miniconda-based testing on Travis-CI

Experimental branch that uses miniconda rather than platform
python to test.  Has some advantages in that it is simple to reconfigure
alternative combinations of NumPy, SciPy, Cython and pandas easily,
at least as long as they are provided by Anaconda.
ENH: Alternative travis script that uses Anaconda via Miniconda

Provides an alternative method to test on Travis using Miniconda
that has some advantages from the current system.

- All binary, so no time spent building
- No branching in the execution steps
- Support for up-to-date requirements which are important to test

Also includes a small change to tools/matplotlibrc which changes the backend
to Agg to avoid Tk-related errors on Travis.  Agg is alays available and does not
depend on Qt or another toolkit.

Closes #1500
Changed build configurations to match those discusses in #1523
Fixed config for Python 3.3
Attempt to inspect segfault
Final fixes to remove redundant code from travis config file
Final fixes to remove redundant code from travis config file
Added 4th build configuration

New configuration will always be on the most current versions using Python 2.7
Fixed conda-related issue which allows for no MKL
Added option for cvxopt to Python 2.7, Numpy 1.7 config
Merge pull request #1523 from bashtage/travis-miniconda

MAINT: Use miniconda on Travis.
CLN: Refactored so that there is no longer a need for 2to3

The codebase has been refactored so that it can exist in a single, unified base.
The strategy closely followed six and pandas.compat, but does not involve any further
dependencies.

The compatability location has been renamed form compatnp, which housed compatnp.py3k, to
just compat, and the main py3k compatability files are in __init__.py so that they can
be directly accessed
Rolled back absolute imports in api.py
Refactored compatnp to compat and moved all py3k to __init__. compatnp
is not the correct name, and it makes more sense for compat to be the
location of any backward/forward compatability code using compat for
the majority of the py3k code and submodules np (or numpy) for numpy and scipy.
Final removal of 2.x print
Fixes reduce-related issues
Removes extra .items() and replaced with iteritems.
Corrected typo in import BytesIO
Many small fixes related to things missed that are not covered by tests, including
raw_input
Removed redundant parentheses that produced tuples in print statements
Rolled back a small error in the previous commit
Fix broken execfile fix
Removed unnecessary use of lzip and lmap
Imported zip and map from compat where used