docs: fix up whitespace in mux_generic(9) manpage

Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>
NML: improved debugging in interp_list

Show gets in addition to showing appends.

Also show *which* interp list is being manipulated, on both .append()
and .get().

Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>
docs: note that linuxcnc is available for ubuntu and debian

... But dont try to make the case for Ubuntu in our docs.

Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>
docs: update copyright years to 2014

Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>
docs: better link to the mailing list

Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>
Merge remote-tracking branch 'origin/2.6' into 2.7