2.2.0: FindAndModify

• Merged PR #44: Add equals() methods for wrapper classes - @thekid
• Merged PR #45: Implement Collection modify() and remove() via
  https://www.mongodb.com/docs/manual/reference/command/findAndModify/
  (@thekid)
• Fixed upsert() inconsistency with update() and delete() in how
  it handles the query parameter
  (@thekid)