Update MDLMendeleyAPIClient GET/POST/PUT/DELETE methods to return request operations instances

Update MDLDocument upload file method to return request operation instance
Add update details method to MDLDocument
Fix document creation type parameter being ignored
Update MDLDocument to use an array of URLs
Prevents warnings caused by AFNetworking dependency
Add create document method to MDLDocument
Fix crash when parsing malformed URLs
Update MDLDocument with star/read status
Prevent crashes when parsing malformed documents
Update MDLDocument to provide MDLFile instance for uploaded files
Update MDLAuthor with forename and surname components
Merge branch 'master' into development
Add citation key property to MDLDocument
Merge branch 'development' of github.com:shazino/MendeleySDK into development
Merge branch 'master' into development
Update README for v1.3
Add citation key property to MDLDocument
Merge pull request #9 from shazino/development

MendeleySDK v1.3