License-expression

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Added
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- Add ability to render WITH expression wrapped in parenthesis

Fixes
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- Fix anomalous backslashes in strings

Changed
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- Update the thirdparty directory structure.

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Added
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- New version of boolean.py library
- Add ability to leave license expressions unsorted when simplifying

Changed
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- updated travis CI settings

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- Initial release
- license-expression is small utility library to parse, compare and
simplify and normalize license expressions.