Merge pull request #8 from chaimleib/konstantint-master

merged @konstantint's modifications to core
Merge pull request #9 from chaimleib/konstantint-master

fixes for setuptools, Python 2/3 compatibility and tests
added testall.sh script
removed redundant tests from intervaltree.py
removed test in Python 3.2, added test for Python 2.6
added travis-ci build status badge
README typo
restored support for Python 3.2
README now says we have Python 3.2 support
updated CHANGELOG [ci skip]
added tests for queries on empty tree
fixed crash for begin() and end() when tree is empty
more empty tree query tests
whitespace only
updated future improvements section\n[ci skip]
link to issue tracker in Future improvements\n[ci skip]
link updates [ci skip]
add: Interval.is_null(), check not iv.is_null() on IntervalTree init
added tree copying tests
add: member validation to IntervalTree.verify()