Add coords() and map_coords() utils.

Coords() yields all coordinate tuples from a geometry or
feature object.

Map_coords() maps a function over all coordinate tuples and returns
a geometry of the same type. Useful for translating a geometry in
space or flipping coordinate order.
Enable Python based runtests
Embed the test runner in setup.py
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Install unittest2 for Python 2.6
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Merge pull request #33 from frewsxcv/enable-coveralls

Add coveralls support
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Merge pull request #31 from frewsxcv/toc

Add table of contents to README
Merge pull request #34 from sgillies/master

Add coords() and map_coords() utils.
Badge should point to master
Convert pytest to unittest
Add python 3 support for coords
Document new utilities
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Simplify getattr logic
Add tests for base.py
Fix import whitespace
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