Update references to legacy URLs to support spring.io
Merge pull request #116 from royclarkson/url-updates

Update references to legacy URLs to support spring.io
Add generic/configurable connection factory and service provider implementations. SOCIAL-396
Support OAuth 1.0 in addition to 1.0a in generic connection factory. SOCIAL-396
Add ability to carry access token as query parameter for providers that don't support Authorization header. SOCIAL-396
Add message converter for form-encoded data to flat Map. SOCIAL-397
Add missing headers
Edits and additions to JavaDoc.
Polish
Add Thymeleaf dialect for Spring Social. SOCIAL-398
Add mavenCentral() repository to fix broken build.
Removed mavenLocal() dependency now that Thymeleaf dependency is resolved in libs-snapshots