Add support for "R" models

"U" models are explicitly supported, and it's not made clear that "R" models are equally supported.
Adding support for "W" models
Added "W" & "R" support from README.txt to .md
Added (unsupported) build profile for RT-AC56S.  Untested.
Updated prebuilt AC66U/MIPS blobs from 376_2524 GPL
Remove accidentally committed merge reject file
Merge pull request #713 from jasonh-n-austin/master

Add support for "R" & "W" models to README.md
Merge branch 'master' of github.com:RMerl/asuswrt-merlin
Add option to specify that router should download the Download Master packages from the Internet when installing it, but consider that other apps such as AiCloud and cloudsync are already built-in.  This allows to save 8 MB of space on the AC56/AC68 firmware
Added (unsupported) build profile and files for RT-N18U.  Untested.
webui: Treat the RT-AC56S the same as an RT-AC56U/R; report CPU temp for RT-N18U (untested)
stealth mode: Add (untested) support for RT-AC56S
Removing RT-N18U profile since it fails to build - probably various binary blobs need to be different"
Revert "Added (unsupported) build profile and files for RT-N18U.  Untested."

This reverts commit 232486f7ca84a7aa3a02d83dba1dd159f13ef5f4.
Remove RT-AC56S profile since it doesn't work either - requires non-SMP binary blobs.
Revert "Added (unsupported) build profile for RT-AC56S.  Untested."

This reverts commit 9662d7935deaca55162a12328afb9be170e689be.

Conflicts:

	release/src-rt/target.mak
Bumped revision to beta 1
libupnp: Remove empty file to instruct the Makefile that the library is already compiled and linked
webui: PPTPD was getting enabled every time you used Apply while on the PPTPD VPN Server page
Updated documentation
Synced emf.o ARM version with the latest GPL release
ufsd: Sync with latest GPL (cosmetical change only)