[doc] update TOC
[doc] add cache section
[doc] add more content, reorder sections
[doc] update TOC
[doc] explain HAL JSON/XML, and default XML serializer
[doc] add missing link
[doc] typo
[doc] add note about XmlRoot param for embedded resources
[doc] add 'configuring metadata locations'
Refactor basic Collection support

Rename Collection class to SimpleCollection
Add exclusions to the collection relation so the collection works with groups.
Add relations parameter to the constructor to provide vustome relations
Merge pull request #90
Rename test class (SimpleCollectionTest)
[doc] update documentation related to collections
Add test + doc for PagerfantaFactory
[doc] fix code examples
[doc] fix code examples again
Fix PaginatedCollectionTest
Fixed undefined variable
[Docs] Proofreading the documentation

Numerous, minor tweaks.
Merge pull request #102 from pborreli/fix-undefined

Fixed undefined variable