vendor: add option to build TWRP Recovery [1/2]

ps1: this is proof, not merge
ps2: update message
ps3: set by default cwm, then it will be overwritten if you use TWRP
ps4: fix derp cwm to cm
ps5: change summary
ps6: another change summary :D
ps7: again

Change-Id: Ifc70277c294e1434603962bc6d8663b0c314fa68