Feature/query service use jackson

This covers work done on the query service for Europa. Stories included in this work include: 
TA20880: Clean up Query API.
TA20884: Return tags with query results.

Other changes include:
-much refactoring of code (still much to be done)
- Use of Jackson to read/write JSON
- removal of dead code
- and many other fixes

Modifications to API:
- removed grouping
- fixed downsampling
- throw error if '*' is specified in a query tag
- 'emit' was removed and added back again
- added downsampleMultiplier to control number of points retrieved from openTSDB per point requested. This fixes an issue where openTSDB averaging of x-values can result in empty buckets if the desired resolution is specified directly.