Refactor rescue objects so that they can support derivation.
Factor out legacy rescuer code to perform legacy project rescues.
Create new symbol library table rescuer for rescuing symbol library table
based projects.
Perform the correct rescue type on project load.
Add symbol library table remapping support to the tools menu for run on
demand as applicable.
Add flag to SCH_SCREENS::UpdateSymbolLinks() to allow forcing the symbol
link updates when the library modification hash has not changed.
This commit was too broad and not cognizant of the purpose of the class
UTF8.
Add MAYBE_VERIFY_UTF8() macro, which can trap non-UTF8 encoded strings in
debug builds.
Use that macro conditionally in class UTF8 to trap non-UTF8 encoded strings
being put into UTF8 instances.