MIPS update and tree re-sync with GPL 2678 from RT-N16:
Cleaned a few prebuild/prebuilt paths to be in-sync with GPL.
Fixed out-of-sync code with GPL for u2ec
Fixed out-of-sync makefiles with GPL for nvram
toolchain: Added the 4.2.3 toolchain Asus now uses to compile the MIPS kernel.
I suspect this is so Broadcom-provided modules such as ctf will be compiled with
the same toolchain as the rest of the kernel.
toolchain: remove the Kernel 2.4 toolchain - we don't have any model based on Kernel 2.4
toolchain: remove unused symlink
Updated documentation
sqlite3: re-enabled threadsafe support.  This fixes minidlna no longer supporting inotify-based updates.  I assume Asus disabled threadsafe support for performance reason - it is also used by the TrendMicro DPI engine.
Updated documentation
webui: fix incorrect top margin and stretched font when enabling AiCloud
dpi: when the closed-source DPI engine restarts, it flushes part of the iptables, breaking the NAT loopback and probably other things as well.  This is an attempt to reapply all firewall rules in those DPI restart calls I was able to intercept in the open-source parts.  Unsure if these are enough.
Bumped revision to alpha 3