2.0.0: Command options

The second major release adds the possibility to pass additional options to all commands, including read preference as well as read and write concerns.

• Merged PR #40: Implement read and write concerns, implementing #11.
  See https://www.mongodb.com/docs/manual/reference/read-concern/ and
  https://www.mongodb.com/docs/manual/reference/write-concern/
  (@thekid)
• Merged PR #41: Remove deprecated Collection::command(), superseded in
  1.4.0 with the new run() method, see #21.
  (@thekid)
• Merged PR #39: Refactor all methods to receive options varargs. Passing
  additional options to methods such as find can be accomplished by
  creating Options instances.
  (@thekid)

1.15.0: Authentication mechanism negotiation

• Merged PR #38: Support authentication mechanism negotiation. This way,
  we default to using SCRAM-SHA-256 if the server supports it as mandated
  by the specification.
  (@thekid)

1.14.0: SCRAM-SHA-256

• Merged PR #37: Implement SCRAM-SHA-256 authentication. Implements #8
  (@thekid)

1.13.0: Fix "cursor id ... not found"

• Merged PR #36: Introduce Commands class which keeps all messages on the
  same connection, fixing #29 (Error: cursor id "..." not found). Note:
  This changes the low-level internal API inside the io package!
  (@thekid)

1.12.0: Document property references

• Merged PR #35: Return document properties by reference - @thekid

1.11.0: Optional regex modifiers

• Merged PR #34: Make it possible to omit regex modifiers - @thekid

1.10.0: Connection error handling

• Introduced new base class com.mongodb.CannotConnect - @thekid
• Merged PR #32: Fix DNS errors, fixing issue #31 - @thekid
• Merged PR #30: Migrate to new testing library - @thekid

1.9.2: Nearest read preference fix

• Added fix for #28 - reconnecting when using readPreference nearest
  fails with Undefined array key "" error.
  (@thekid)

1.9.1: DNS error handling

• Merged PR #27: Handle errors from dns_get_record() - @thekid

1.9.0: Protocol accessor

• Merged PR #26: Add MongoConnection::protocol() - @thekid
• Fixed IPv6 handling in connection DSNs - @thekid