Contains the type refactorings. The refactorings in this
package are type based refactorings, for instance move
a class to a different package or rename a class.
This package also contains a number of different visitors
that traverse the entire tree of source files, since
type based operations have the possibility of changing
all the source files in the system.
Beneath that are TransformAST objects which perform a
single unit operation such as renaming a type. The
actual work isusually done by the associated visitor
object.