When a number has a suffix the lexer state didn't record the number of
characters consumed for this suffix. This made the lexer state be 2-3
characters short in its line location reporting until it encountered a
newline character. It did not otherwise corrupt the state of the lexer.
- Exposes all errors in the header file so any user of the api can test
for the specific error conditions
- Mark all static error pointers as const
- Move generic errors into error.h
- Name all errors err_modulename_* for errors that belong to a specific
module and err_* for generic errors.
