Update firmware tools to generate 16M firmware for hacked routers.
Change mktplinkfw for 16M flash MOD routers.
Change feeds to github.
firmware-utils/mktplinkfw: add support for the TL-WR720N v3 board
ar71xx: add profile and build image for the TL-WR720N v3 board
ar71xx: add user-space support for the TL-WR720N v3 board
ar71xx: add kernel support for TPLINK WR720N v3 Add support for TPLINK WR720N v3 which has 4MB flash, 32MB ram, 2 ethernet interfaces, 1 USB 2.0 port.

The patch is mostly a modification from mach-tl-wr703n.c.
GPIO numbers for the slider switch is from mach-tl-mr3020n.c.
Commit patches for openwrt enhancement.
Update feeds sources mwan3, dnscrypt-proxy, shadowsocks-libev.