Add BUGS and redirect STDERR to /dev/null

Redirecting STDERR to /dev/null removes the error about the MD5 digest
algorithm being deprecated. The error is exactly:

    :gpg: WARNING: digest algorithm MD5 is deprecated
    gpg: please see http://www.gnupg.org/faq/weak-digest-algos.html for more information
Test if <FILE> is an exported public PGP key.
Add support for GnuPG v2 in case v1 is not installed.
Implement upstream bug work around and multiple key support.

See upstream bug #1640:
    - https://bugs.g10code.com/gnupg/issue1640

Also implement the ability to process multiple keys on the command line.
Move ASCII art image into an array element.

By moving the art into an array, this sets me up for getting ready to print
off a keyart page for keysigning party organizers, by treating each art as
a logical unit individually.
Add an ANSI heat map to the art output.
Update BUGS with ANSI art bug.
Revert back to supporting only 1 key at a time.
Add arguments for printing ANSI color

* Key prints in plain text by default now.
* Add '-a' and '--ansi' for ANSI output printing of the key.
* Cleaned up some of the code for the new argument handling.
Add documentation and example script

* Add simple Bash shell script for creating keyart with 5 keys per line.
* Add documentation about how to create a key signing party worksheet.
Add nroff manual page
Fix Start and End ('S', 'E') tokens while using ansi art
change from using a keyfile as an argument to a keyid
rework colors, with 1 less blue, and add white at end
change documentation wording to reflect the new change of not needing an exported key file
Change algorithm, add multiple key support

The algorithm now supports the OpenSSH algorithm, where 2-bit pairs are
read in little endian, rather than reading the whole string in big endian.
As a result, documentation is updated to reflect this.

The script now accepts multiple files, but passing -i|--id is required, as
future support for -k|--keyring will be needed as an alternative.
logic cleanup on flipping bit pairs
Much code update and many manpage update

The '-i|--id' and '-k|--keyring' options are now mutually exclusive, require at
least one argument, and one of them is required to be passed to the command.
Currently, '-k|--keyring' code is not implemented- coming soon.

Did some code changing to introduce a 'test_env()' function and moved logic
around a bit making it easier to work with. Also micro-optimized creating the
little endian array.

Updated the keyart.1 manpage to reflect the new options.
fix regression of ansi option
closer PEP8 conformance