Translator Exceptions – Expressions

The get expression function was modified to throw errors.  The return type was removed since a no exception return now indicates success.  The temporary error tokens for errors no longer need to be created.  The Done status that was previously returned for success was no longer used, so this status enumerator was removed.

All callers of the get expression function were modified for an error being thrown, which for the most part meant catching errors instead of looking for an error return status.  However, there was an issue with how errors were processed when an unexpected unary operator token appeared.

When an unexpected unary operator appeared, get expression returned an "expected binary operator or end-of-statement" error along with the unary operator token.  When another error was appropriate, the caller essentially ignored this error when it a unary operator, and threw the appropriate error.  Now that get expression throws an error, there is no token returned, so callers cannot look for a unary operator token.  The callers were were modified to look for this error and then throw the appropriate error.

[branch misc-cpp-stl commit 697a0d25d8]