Replace kohana db with a standalone DB library

[rjmackay]

Needs to support:

• Mysql
• Postgis
• Mssql (nice to have)
• SQLite (for testing) + spatialite?

Need a query builder, and dbal.. but migrations stay with phinx, and no ORM.

Aha! Link: https://ushahiditeam.aha.io/features/PROD-727

[rowasc]

Pending start using Lumen with Eloquent https://github.com/ushahidi/platform/pull/1663