v4.12.0-p0 hunterized

• add HunterGate v0.11.0
• add Hunter v0.26.4
• add package ippicv
• add package ZLIB
• add package TIFF
• add package jasper
• add package PNG
• add package Jpeg
• add package WebP
• add package Eigen3
• add package OpenEXR
• Add OPENCV_WITH_EXTRA_MODULES option
• add Qt5 backend with static link support
• add package FFmpeg
• fix for config root-WIN32
• disable external download when building with Hunter

v4.10.0-p0: hunter: disable external download when building with Hunter

The only package that is allowed to use `ocv_download()` is `IPPICV` as
it is tricked to use the Hunter provided file.

v4.5.5-p0

Fix protobuf-host location

v3.4.10-p0

Merge pull request #4 from ThomasGuerneve/3.4.10-hunterised

3.4.10 hunterised

v4.2.0-p0

Merge pull request #2 from inuaimi/hunter-4.2.0

Support for opencv-4.2.0

v4.1.1-p0

Merge pull request #1 from kumaakh/hunter-4.1.1

Support for OpenCV4.1.1