Add mechanism for early object repairs on a per-name basis.

Adds the framework to allow object repairs very early in the
return object analysis. Enables repairs like string->unicode,
etc. Bob Moore, Lv Zheng.
Split object conversion functions to a new file.

New file, nsconvert.c, for return object conversion functions.
Created in preparation for new conversion functions forthcoming.
Return object repair: Add string-to-unicode conversion.

Used for the _STR and _MLS predefined names.
Lv Zheng.
Return object repair: Add resource template repairs.

Fixes several possible problems with resource templates returned by
_CRS/_PRS/_DMA predefined names. Lv Zheng.