Add a simple query system

- Extend clint.textui.prompt with a query function.
- Add clint.textui.validators to validate the user input.
- Add a prompt example showing different usages.
- Update the README to demo the query function.
Always dedent when leaving indent context manager.
Display elapsed time when the progress bar is complete
Update AUTHORS
Merge pull request #116 from jta/master

Always dedent when leaving indent context manager.
Merge pull request #114 from aeby/master

Add a simple query system
Merge pull request #118 from thenovices/master

Display elapsed time when the progress bar is complete
Fix syntax error prevent installation in Python 3.x

An exception handled in textui.prompt was being handled using the old-style
`except Exception, e:` syntax. I've updated this, but specifically have not
addressed the potential issue of catching a bare exception.
Merge pull request #123 from lyndsysimon/python3

Fix syntax error prevent installation in Python 3.x
remove buildable artifacts from documentation

The _build directory contains documentation artifacts that should be
generated by a sphinx build and typically should not be committed.
Add an ignore for the _build subdirectories.

The build subdirectories are only used to house generated documentation
and typically shouldn't be committed.
Add the documentation to the sdist tarball.

Currently the documentation is not included in the sdist provided by
PyPi due to this missing Manifest line.
Merge pull request #124 from alunduil/include-docs-in-sdist

Include docs in sdist
More python 3 fixes
Merge branch 'master' of https://github.com/kennethreitz/clint
v0.4.0
Decision to hide must be at runtime, not at import
v0.4.1
fix gitignore and docs
Changed var name.