change concat transformer, config with tree hierachy
improve code readability
implement abstract methods
change function parent node claculation to transformer classes
improve code readability
add Contains operator transformer
register ContainsTransformer class
add constant property value to Constant model
add ConstantTransformer class
Register Constant Transformer and implement in traverser
remove equel operator from pallet
edit code change after model change
Merge pull request #33 from wso2-dev/master

Fixing TOOLS-2448
improve code readability
Merge pull request #49 from lsdeva/master

contains, constant operator transformer added. conacat transformer changed