* Adjust build environment as per https://docs.opencv.org/3.1.0/d5/de5/tutorial_py_setup_in_windows.html and https://wiki.python.org/moin/WindowsCompilers#Which_Microsoft_Visual_C.2B-.2B-_compiler_to_use_with_a_specific_Python_version_.3F

* The best practice is to only use requirements.txt for deployments, not for packaging

* ignore PyCharm metadata

* refactor to be more modular

* the warnings are irrelevant in older versions

* v110 toolset might introduce dependency on older runtime not likely to be present in newer systems, potentially breaking upgrade

* build locally with scikit-build

* adjust appveyor config to local build

* cleanup

* DLL load works without

* fail appveyor build immediately when one job fails

* * cmd doesn't expand globs
* - diplication
* - WinXP-related bits
* pip erroneously considers cv2/ as installed package when in sourceroot
* require CMake output entries to be found
* 3.5+ uses different .pyd naming scheme
* .pyd is placed differently in Linux
* DLL is only in Windows

* ignore temporary config files

* Yet another .pyd naming convention in Py35 Linux.
Screw checking.

* Update setup.py file to flag compatibility with Python 2.7-3.4-3.5-3.6 (#57)

# Conflicts:
#	setup.py

* Adjust build environment as per https://docs.opencv.org/3.1.0/d5/de5/tutorial_py_setup_in_windows.html and https://wiki.python.org/moin/WindowsCompilers#Which_Microsoft_Visual_C.2B-.2B-_compiler_to_use_with_a_specific_Python_version_.3F

* The best practice is to only use requirements.txt for deployments, not for packaging

* ignore PyCharm metadata

* refactor to be more modular

* the warnings are irrelevant in older versions

* v110 toolset might introduce dependency on older runtime not likely to be present in newer systems, potentially breaking upgrade

* build locally with scikit-build

* adjust appveyor config to local build

* cleanup

* DLL load works without

* fail appveyor build immediately when one job fails

* * cmd doesn't expand globs
* - diplication
* - WinXP-related bits
* pip erroneously considers cv2/ as installed package when in sourceroot
* require CMake output entries to be found
* 3.5+ uses different .pyd naming scheme
* .pyd is placed differently in Linux
* DLL is only in Windows

* ignore temporary config files

* fail fast on error

* * custom build logic should be unneeded now, will uncomment as needed

* use the latest upstream multibuild

* enable tracing
- more suspicious things

* save some build time

* these somehow cause "Server does not allow request for unadvertised object" for GitHub

* Revert "use the latest upstream multibuild"

This reverts commit 915ba421f97acebb3edcf55b5e46ea7aab8fea42.

* Yet another .pyd naming convention in Py35 Linux.
Screw checking.

* Update setup.py file to flag compatibility with Python 2.7-3.4-3.5-3.6 (#57)

# Conflicts:
#	setup.py

* add diagnostics

* * Use upstream multubuild due to the forked one abusing prebuild as build

* save some time

* looks like clean_code() isn't required

* * Don't make CMake try Ninja first
* MacOS LAPACK on Travis is still broken

* See build progress as it goes

* update submodules on demand

* fetch source in time for find_version.py

* use custom docker image

* use custom multibuild

* bump submodule

* Linux/OSX are supposed to build with Qt support

* * make shallow copies to save on download time
* manylinux git is an old version

* * clean up redundant syntax
* reformat codeas YML multiline with dedent

* IPP IW broken in Linux

* + ffmpeg patch

* additional deps required due to multibuild bug

* +cv2.data

* Use upstream multibuild with monkey patch

* don't do anything if upload not needed

* filter out irrelevant debug output

* * clean up unused scripts
* inline the remaining standalone scripts

* https://github.com/matthew-brett/multibuild/issues/106 fixed

* * bump OpenCV version to 3.4.0

* * https://github.com/opencv/opencv/pull/10011 is available in 3.4.0
* allow for if the sourcetree is a submodule

* * don't reinstall whatever happens to be preinstalled
* re-add workaround for https://github.com/travis-ci/travis-ci/issues/9055

* * rearrange custom CMake flags
* -DWITH_GTK=OFF proved to be unneeded, gthread is among manylinux requirements

* fix linux detection to work in 3.3+, too

* fix data path for other OSes

* don't do anything unless deployment is requested

* use upstream ``devel`` multibuild

* restore from backup after rebase

* catch fetch error

* use `devel` multibuild

* comment not using --depth

* remove redundant command after merge