QVT — rules for solving type identifiers are missing in the QVTOperational syntax

ISSUE: The rules for solving type identifiers are missing in the QVTOperational syntax.

The resolution rules when referencing types identifiers is missing in the
QVTOperational syntax. For instance it is not clear weather unqualified type references
should first be searched in the modeltype packages or in the transformation module.

Add a new sub-section 8.4.7 (after sub-section 8.4.6 BNF) named "Solving type identifiers" with the following content:

When referring to a type within an operational transformation definition it is possible to either qualify the type name with a model type or a package name, or, alternatively, leave the name of the type unqualified. In the latter case, a list of rules applies to resolve the symbol into the denoted type. If the resolution rule provides more than one result the specification is erroneous.

• Firstly a type definition existing at the level of the current module (a transformation or a library) is searched.
• In not found, all the packages of the model types declared in the module are recursively visited to found a type with the same name.