Merge pull request #306 from gavincornwell/1.4-dev

MOBSDK-763 (mandatory aspects) and updates to reflect spec
Merge pull request #307 from gavincornwell/1.4-dev

Added test to prove MOBSDK-711 could not be reproduced.
Merge pull request #308 from gavincornwell/1.4-dev

MOBSDK-752: As a developer I can retrieve model definitions for types and aspects using the iOS SDK
Merge pull request #309 from gavincornwell/1.4-dev

Integrated latest ObjectiveCMIS library and fixed model definition tests to work across all server versions