STREAMS-93 | Updated the Hashtag POJO schema in tweet.json, added dependency on streams-processor-urls in streams-provider-twitter (to get LinkDetails POJO) and updated all Twitter serializers to add in generic extensions
STREAMS-93 | Moved duplicated addExtensions() function up to TwitterJsonActivitySerializer class as a utility function
STREAMS-93 | Removed url additions to extensions attribute
STREAMS-93 | Removed dependency on streams-processor-urls
Merge branch 'master' into STREAMS-93
Merge branch 'master' into STREAMS-93

Conflicts:
	streams-contrib/streams-provider-twitter/src/main/java/org/apache/streams/twitter/serializer/TwitterJsonActivitySerializer.java
	streams-contrib/streams-provider-twitter/src/main/java/org/apache/streams/twitter/serializer/TwitterJsonRetweetActivitySerializer.java
	streams-contrib/streams-provider-twitter/src/main/java/org/apache/streams/twitter/serializer/TwitterJsonTweetActivitySerializer.java
STREAMS-93 | Moved duplicated activity/actor methods to TwitterActivityUtil class. Ensured that those new methods were comprehensive
STREAMS-93 | Properly setting image in actor object