UnmarshalStream: Changed it to be like MRI and look for encoding data in all the instance variables, and only use the last one.  All I did was remove the "i==0" condition in defaultVariablesUnmarshal and adjust the indentation accordingly.
Merge branch 'jruby-1_7'

Conflicts:
	core/src/main/java/org/jruby/runtime/marshal/UnmarshalStream.java
Add test:dist target and enable (with errors) in CI.
Merge branch 'jruby-1_7'

Conflicts:
	.travis.yml