repo: update from 1.19 to 1.20

Signed-off-by: Christopher Larson <kergoth@gmail.com>
tmx: when no arguments are given, show existing sessions

Signed-off-by: Christopher Larson <kergoth@gmail.com>
abspath: add 'relativeto' cmdline option

Signed-off-by: Christopher Larson <kergoth@gmail.com>
fish: drop abspath function, use the script

Signed-off-by: Christopher Larson <kergoth@gmail.com>
git/exclude: exclude .nfs*

Signed-off-by: Christopher Larson <kergoth@gmail.com>