This commit removes the public key named "LinuxCNC 2.6 Release Manager"
and adds a new public key named just "LinuxCNC Release Manager".
I'll use the new key to sign future releases in 2.7 and later.
The new key has the email address <emc-developers@lists.sourceforge.net>,
instead of <seb@highlab.com>.
Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>
Add a gnupg keyring containing just the public part of the keypair used
to sign release tags.
Also change the githelper script to use the keyring in the git repo
instead of the one in the caller's home directory.
Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>