* First pass.
* Improvements and fixes
- Update usages of BcolzMinuteBarWriter
- Updates with rebuilt example data
- Expose calendar from BcolzMinuteBarMetadata instead of calendar_name
- Keep market_opens and market_closes in metadata for compatibility
* Store start_session and end_session in minute bcolz metadata
- start_session replaces first_trading_day
- Add end_session to limit to correct days
* For last_available_dt, get last close from calendar to maintain tz
* Bumps version and handles earlier versionson read
* Rebuilt example data on python 3
* Indicate metadata fields that are deprecated