Make separate class for evaluating ERB
ZEPPELIN-106 apply non null string
ZEPPELIN-106 make ZContext to a interface and create two implementation of them, ZLocalContextImpl, ZGlobalContextImpl
ZEPPELIN-106 move ZWebContext into context package
ZEPPELIN-106 add a testcase which requires global erb evaluation
ZEPPELIN-106 two level erb evaluation, global level (whole statments) and local level (one by one)
Add more zql erb template test case with conditional branch
Handle exception on ins.close()
ZEPPELIN-106 Get Scriptengine using singleton pattern
ZEPPELIN-106 Make getSingletonScriptEngine thread safe
Update project homepage address
Merge branch 'master' into global_zql_erb_scope

Conflicts:
	zeppelin-zengine/src/main/java/com/nflabs/zeppelin/zengine/stmt/Q.java
	zeppelin-zengine/src/main/java/com/nflabs/zeppelin/zengine/stmt/Z.java
	zeppelin-zengine/src/main/java/com/nflabs/zeppelin/zengine/stmt/ZQL.java
Merge pull request #58 from NFLabs/global_zql_erb_scope

Global zql statements evaluation