Enhancements to athena-cli

[bryanck]

Hi, we are using athena-cli across our company, and made a few enhancements based on feedback from users. We'd love to get your feedback on these changes and hopefully merge them in.

Some changes include:

• Support different output formats in shell mode
• Fixes to character set handling
• Iterate over results where possible to reduce memory use
• allow lower case commands to be multiline
• added an option to truncate the width of the aligned format and default to line wrap
• a couple of minor bug fixes

[bryanck]

Cool, thanks for the feedback and consideration