byobu: Add new package

From the website:
Byobu is a GPLv3 open source text-based window manager and terminal
multiplexer. It was originally designed to provide elegant enhancements
to the otherwise functional, plain, practical GNU Screen, for the Ubuntu
server distribution. Byobu now includes an enhanced profiles, convenient
keybindings, configuration utilities, and toggle-able system status
notifications for both the GNU Screen window manager and the more modern
Tmux terminal multiplexer, and works on most Linux, BSD, and Mac
distributions.

Adapted from the old packages feed:
https://git.openwrt.org/?p=openwrt/svn-archive/packages.git;a=tree;f=utils/byobu

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

utils/byobu/patches/005-monitor-overlay.patch

@@ -0,0 +1,28 @@
+--- a/usr/lib/byobu/disk
++++ b/usr/lib/byobu/disk
+@@ -26,7 +26,10 @@ __disk_detail() {
+ __disk() {
+ 	local out="" MP="" size="" pct="" unit=""
+ 	# Default to /, but let users override
+-	[ -z "$MONITORED_DISK" ] && MP="/" || MP="$MONITORED_DISK"
++	MP="$MONITORED_DISK"
++	[ -n "$MP" ] || {
++		grep -q ' /overlay ' /proc/mounts && MP=/overlay || MP=/
++	}
+ 	case $MP in
+ 		/dev/*) MP=$(awk '$1 == m { print $2; exit(0); }' "m=$MP" /proc/mounts);;
+ 	esac
+--- a/usr/lib/byobu/disk_io
++++ b/usr/lib/byobu/disk_io
+@@ -42,7 +42,10 @@ getdisk() {
+ __disk_io() {
+ 	local part= i=
+ 	# Default to disk providing /, but let users override with MONITORED_DISK
+-	[ -z "$MONITORED_DISK" ] && mount_point="/" ||  mount_point="$MONITORED_DISK"
++	local mount_point="$MONITORED_DISK"
++	[ -n "$mount_point" ] || {
++		grep -q ' /overlay ' /proc/mounts && mount_point=/overlay || mount_point=/
++	}
+ 	# By default, we won't bug the user with the display of network traffic
+ 	# below DISK_IO_THRESHOLD in kB/s; override in $BYOBU_CONFIG_DIR/status
+ 	[ -n "$DISK_IO_THRESHOLD" ] || DISK_IO_THRESHOLD=50