Builds on RHEL 8.2 systems are failing due to this issue.

See [1] as to why this is necessary.

I used the following command to identify files that need this fix:
find . -type f -executable | /usr/lib/rpm/redhat/brp-mangle-shebangs

I also updated the copyright notices as needed.

1. https://fedoraproject.org/wiki/Changes/Make_ambiguous_python_shebangs_error

Fixes: 1ca0323e7c29 ("Require Python 3 and remove support for Python 2.")
Signed-off-by: Greg Rose <gvrose8192@gmail.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

Perl is unfashionable and Python is more widely available and understood,
so this commit converts one of the OVS uses of Perl into Python.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Justin Pettit <jpettit@nicira.com>

Replaced all instances of Nicira Networks(, Inc) to Nicira, Inc.

Feature #10593
Signed-off-by: Raju Subramanian <rsubramanian@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

Some versions of "dot" put two spaces after the "node" keyword instead of
one, which didn't match the regular expression used in dot2pic.  This
commit changes dot2pic not to care about the number of spaces in "node" and
"graph" lines.  (The "graph" lines weren't actually a problem but I don't
see a reason to be picky about them either.)

Different versions of "dot" still produce different output for the same
input, but I don't see how to avoid that.

Reported-by: Justin Pettit <jpettit@nicira.com>

Recent versions of Graphviz no longer support output to PIC format, so this
commit adds our own internal translator from dot's "plain" output format
to PIC format.  The "plain" format works best with slightly different
"dot" input (advised by the Graphviz manual description of the "plain"
format) so this commit also adjusts ovsdb-dot's output.