Enhance Variables to support Integer/Float

[wbari]

Currently Variables inside VariableSet and AnnotationSet support the following data types:
CATEGORICAL, NUMERIC, OBJECT, BOOLEAN, TEXT. Integer, float, double, long all are supported under NUMERIC category and doesn't respect datatype on persistence. User would like to distinguish among these data types, store data with proper type and later retrieve it as well.

For example : INTEGER 1 must be stored as 1 and returned as 1 as well whereas Double 2.0 must be stored as double and returned as 2.0

[pfurio]

NUMERIC variable type has been removed and two new variables have been added, INTEGER and DOUBLE as can be seen here.

• A migration script will be needed to change existing NUMERIC variable types for DOUBLE

[pfurio]

Migration script can be found in https://gist.github.com/pfurio/ace5d31a4f42750801ac4070bd830e8b