New datatypes conversion framework:

 - added the new interface o.a.v.util.introspection.ConversionHandler,
   and the new 'runtime.conversion.handler' configuration property
   which let the configuration handler be pluggable.

 - added a default implementation class o.a.v.util.introspection.ConversionHandlerImpl
   that will implicitly convert method arguments between all basic Java data types
   (boolean, numbers, string).

 - added a new Converter<T> interface to represent converters towards type T

 - added a public VelMethod.getMethod() getter to ease the work of people
   customizing introspection

 - added test case ConversionHandlerTestCase

 - removed half-finished IntrospectionCache 'pluggability' feature:
   since IntrospectionCache now needs a ConversionHandler a c'tor argument,
   made it a concrete class and removed IntrospectionCacheImpl.



git-svn-id: https://svn.apache.org/repos/asf/velocity/engine/trunk@1754151 13f79535-47bb-0310-9956-ffa450edef68
35 files changed