Add CategoryFeature.java into avagu package
Add function to calculate category feature
Rewrite category strategy
Add exception Handler
Add exception Handler
Add a tag to code
Add result for False false
Merge branch 'avagunew' of https://github.com/AvaGu/websail-wiki
minor change
link step feature test1
Merge branch 'master' of
https://yuxihe831@bitbucket.org/websail/websailwikifier-client.git

Conflicts:
	src/main/java/edu/northwestern/websail/el/client/api/WebSAILWikifierAPIAdapter.java
Merge branch 'master' of https://bitbucket.org/websail/websailwikifier-client