reuse predefined serializer instead of create new ones
Fix NPE when connected entity doesn't exist
fixing legacy portal
Merge pull request #155 from usergrid/fix-legacy-portal

Fix legacy portal
add Rails compatibility information to README
Merge pull request #156 from usergrid/gridiron-doc-update

document Rails version compatibility
Merge pull request #152 from aweeraman/USERGRID-18

Fix and test for USERGRID-18
Merge pull request #147 from stliu/serializer

reuse predefined serializer instead of create new ones