Eliminate several memory allocations per line when reading thesaurus files
Don't build the dialogue lexer on every use

Building the lexer takes much longer than actually lexing, and since the
lexer is stateless there's no reason not to just make it static.
Fix non-pch compilation
Make AssFixStylesFilter usable statically

Trivially speeds up ProcFrame as constructing export filters isn't free
due to that it has to look up the translatable strings.
Eliminate some warnings