[OPTIQ-247] Add Context and FrameworkConfig
[OPTIQ-324] Add ViewExpander for Planner in Frameworks. Expose additional properties of ViewTable to allow subclassing.
[OPTIQ-326] Fix RelOptUtil ANY type check.
[OPTIQ-325] Use Java list instead of Guava list to avoid null checks in case of SqlTypeExplicitPrecedenceList.
[OPTIQ-323] Override SqlUnresolvedFunction.inferReturnType() to return 'ANY' type so framework implementors can support late bound function implementations.
[OPTIQ-322] Add support for SqlExplain, SqlOrderBy and SqlWith to support SqlShuttle use.
[OPTIQ-321] Add support for overriding implementation of CompoundIdentifier in SqlParser.
Clean up.

Make StdFrameworkConfig a private inner class.