Clean up UtfString.c, two ways.

The class and member init code got pulled out, and put it into
InitRefs.c (for further cleansing in a future change).

The instance creation code got refactored a bit, to keep things
simpler and tidier.

Change-Id: I22d8abff141ea889b3455a1cebcf51e333cd8c92
3 files changed