A ".dd2 <address>" item would get linked to an internal label, but
references to external addresses weren't doing the appropriate
search through the platform/project symbol list.
This change altered the output of the 2019-local-variables test.
The previous behavior was restored by disabling "nearby" symbol
matching in the project properties.
Updated the "lookup symbol by address" function to ignore local
variables.
Also, minor updates to Applesoft and F8-ROM symbol tables.
2828cc8ca7