Fix buffer overflow in mc_net_info_new

Long device name specified as a command line triggers buffer overflow.
Replace strcpy by strncpy to fix this issue.

Reproducer:
$ macchanger -s `perl -e 'print "A"x100'`

Reported in:
https://bugzilla.redhat.com/show_bug.cgi?id=641704
Fix computation of mac list lengths

LIST_LENGTH macro assumed it's used on static lists, but it was used on
dynamically allocated lists instead.  As a consequence, it always
returned -1.
Fix spelling error: endding -> ending

Reported in:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=621698

Original fix by:
David Paleino <dapal@debian.org>

This updated fix makes macchanger to accept both --ending and --endding
for backwards compatibility.  Only --ending is documented in help outage
and man page.
Documentation clean up

Get man page, texi documentation and --help output in sync.
Only use BIA option when setting fully random MAC

macchanger 1.6.0 added -b / --bia option to control whether locally
administered bit should be set on the randomly generated MACs. If this option
is specified, locally administered bit is cleared, and it's set otherwise.

This option is considered when generating fully random MAC (-r / --random), but
also when setting random vendor MACs (-e / --endding, -a / --another, -A). As
locally administered bit is part of the first MAC octet, which is part of OUI,
clearing the bit (default behaviour when -b is not used) breaks all these
random vendor MAC modes, setting MACs that are not for any recognized vendor.

This fixes makes macchanger set or unset locally administered bit when
generating fully random MAC.  Use of --bia option in combination with other
option than --random generates warning.

Upstream bug report:
https://github.com/alobbs/macchanger/issues/1
Change default action to show

Previous default action was to increment MAC by one.  This default was not
documented and is "dangerous" (changes MAC, change is rather subtle and easy to
miss).

This changes the default action to --show, which has already been the default
in Debian packages for a while, see:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=621494

Upstream bug report:
https://github.com/alobbs/macchanger/issues/4
Merge pull request #2 from thoger/1.6.0-bugfix

1.6.0 bugfixes