Add external-program dependency
Fix typename
Fix macrolet
Take database file names as an arg to effects that need it
Fix compile issues
Add missing-file and abl-error conditions
Use lowercase file type descriptions
Add function to generate an effects applicator
Add installer constructor
Add find-installer
Take database file argument in effects that need it
Add effect lookup func
Lookup effects by symbol-name instead of by symbol
Add definstaller macro
Add probes to example installer def