…ATH_RELATIVE_CONFIGCMAKE when not neededThe variable OpenCV_PYTHON_INSTALL_PATH_RELATIVE_CONFIGCMAKE is set inthe if(IS_ABSOLUTE ...), but it is not used anywhere afterwards.A variable of the same name is defined and used in the else() clauseof the same condition, but it is only used within that else() clause.Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

The cv2 Python modules currently reads at runtime some bits ofconfiguration from config.py and config-X.Y.py files, by executingthem using execfile() or similar inside the Python interpreter.Unfortunately, this requires having the .py files themselvesavailable, which may not be the case on embedded systems where onlythe byte-compiled .pyc files are present (the .pyc files are alreadybyte-compiled, and in order to be space-efficient, .py files are notinstalled on some embedded systems).Due to the lack of .py files, importing the cv2 Python modulefails. Since this configuration mechanism is a bit unusual, and alsorequires separate handling for Python 2 and Python 3, this commitreplaces it by using two .ini files, which are generated with the sameinformation as the .py files, but parsed using the standardConfigParser module of Python.config.ini looks like this:[python]binpath = /usr/libwhile config-3.8.ini looks like this:[python]extensionpath = /usr/lib/python3.8/site-packages/cv2/python-3.8If multiple paths are present, they are stored colon-separated, andthey are split again when the configuration files are parsed.The only change relevant mentioning is that the expansion ofLOADER_DIR is now done when the configuration is parsed: if we have anabsolute path, we take it as-is, if there is a relative path, weassume it is relative to LOADER_DIR.Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>