CAY-1966 SQLTemplate/SQLSelect positional parameter binding

* new org.apache.cayenne.velocity package
* generics fixes in unit tests
CAY-1966 SQLTemplate/SQLSelect positional parameter binding

* abstracting Velocity work in an injectable SQLTemplateProcessor service
* more utest cleanup
CAY-1966 SQLTemplate/SQLSelect positional parameter binding

* utest cleanup
for cleaner output of unit tests bridging Cayenne with SLF4J
CAY-1966 SQLTemplate/SQLSelect positional parameter binding

    * positional parameter bindings in SQLtemplate
CAY-1966 SQLTemplate/SQLSelect positional parameter binding

    * positional parameter bindings in SQLSelect
javadocs errors that are failing Java 8 build
javadocs errors that are failing Java 8 build