TODO: Parameterize constraints on ctx->next in validations to accomodate EarlyChange

- Add debug code to print potential codes at each bit length into a file

- act_LZW_literal wasn't firing, needed VDRULE -> AVDRULE
- set table entries to NULL when clearing
- add LZW_firstcode rule
- act_LZW_firstcode returns a HBytes instead of uint

separate n bit codewords from n bit literals/clear/EOD

Also, reorder validations to line up with H_RULE()s in init

TODO: use HCountedArray or HBytes instead of uint8_t*

Reusing tstr worked, but on a second thought, it's not a good idea to memcpy the same string we're scanning. A separate result buffer is allocated and returned instead.

Remove extraneous malloc()/free()s in gethash(). The pointer returned needs to be freed by the caller.

- Buffer returned by strtok() gets freed up by the next time it's called, so we need to strncpy() the contents out
- changed strcpy() to strncpy()

- Allowing a command line parameter to control output file names
- Unused semantic actions (to be cleaned up pending testing)