bootstrap.image: Use error syntax.
peg.ebnf: Throw errors not strings.
asn1: Throw an error not a string.
cpu.8080: Throw an error not a string.
Config.linux: Clean up warnings when compiling with clang on Linux. make CC=clang CPP=clang++
GNUmakefile: Version was still .94, bump it to .96
debugger: Try to be more helpful if linux libraries are not installed. Fixes #774.