Update to v14.15.1

Signed-off-by: Hirokazu MORIKAWA <morikw2@gmail.com>

Update to v12.20.0
Take over maintainership from John Crispin

Signed-off-by: Hirokazu MORIKAWA <morikw2@gmail.com>

Update to v12.19.0
Fixes for the removal of MIPS FPU emulator support.

Signed-off-by: Hirokazu MORIKAWA <morikw2@gmail.com>

Vulnerabilities fixed:
* CVE-2020-8201: HTTP Request Smuggling due to CR-to-Hyphen conversion (High).
* CVE-2020-8252: fs.realpath.native on may cause buffer overflow (Medium).

Imported patches from the debian package.

Signed-off-by: Hirokazu MORIKAWA <morikw2@gmail.com>