Update TODO list

Signed-off-by: Michael Buesch <m@bues.ch>
Move StringIO compat to compat.py

Signed-off-by: Michael Buesch <m@bues.ch>
Add CSV support to symtab parser

Signed-off-by: Michael Buesch <m@bues.ch>
Add standalone symbol table parser

Signed-off-by: Michael Buesch <m@bues.ch>