Add log method to sequelize
Use new log method
Use the custom logging function if defined
Allow passing of winston options
Add centralized logging
Use the info event for common loggings
Revert "Use the info event for common loggings"

This reverts commit 85dfa296e0e54f2161854b8560777d3440d59016.
Don't depend on winston
Remove references to winston
Formatting
Recovered previously implemented behavior
Merge branch 'master' into feature/logging

Conflicts:
	changelog.md
	lib/dialects/postgres/query.js
Fix the tests
Merge branch 'master' into feature/logging

Conflicts:
	changelog.md
Merge pull request #1566 from sequelize/feature/logging

Refactored logging