Fix local compile issue. Improve Makefile.
Fix input action to find its input string
More work on an INPUT action - that I'ma bout to abandon

Function hex2buf() is working, but not completed. However, its very wrongheaded
(I have come to realize).

Saving this work before I go rip it up, but I have a much better implementation
coming.

-   Do more on hex2buf() - it's almost there.
-   Add hex2ing()
Complete work on INPUT action

This completely works now!

- clean up misc code & format problems
- add better doxygen documentation
- change hex2buf() to return length of output buffer
- break out hex2buf() into 4 functions:
    - hex2buf() itself, which calls the other 3
    - validate_hexstring()
    - normalize_hexstring()
    - nhex2int()
- start using bool
- make more consistent when we exit() vs return failing error code
dev note & roadmap udpates