Update Trove classifiers and URL

- update list of supported python versions
- point to github instead of the old cheeseshop site

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document query command

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add a `query` command

as suggested by @leorochael

for continuous integration

Typo fix: 'uuinstall' to 'uninstall' in comment

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debugger: Exit with error code on debugged error

When buildout encounter an error, program exists with error code 1, this
should also be the case when exiting from a debugger session when
running with -D option.

Closing #464

Fix most Deprecation and Resource warnings.

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Fix dependencies between zc.buildout and zc.recipe.egg after zc.recipe.egg 2.0.6 release

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Add 'allow-unknown-extras'