[pkg] parametrize win/osx installer

Makefile

branding/qtinstaller/config/config.xml

branding/qtinstaller/packages/root.win_x86_64/.gitignore

...tinstaller/packages/root.win_x86_64/meta/installscript.js

...ing/qtinstaller/packages/root.win_x86_64/meta/package.xml

branding/qtinstaller/packages/root/meta/package.xml

branding/scripts/gen-qtinstaller

branding/templates/qtinstaller/config/config.xml

branding/templates/qtinstaller/linux-data/readme

branding/templates/qtinstaller/osx-data/post-install.py

...mplates/qtinstaller/osx-data/se.leap.bitmask-helper.plist

branding/templates/qtinstaller/osx-data/uninstall.py

...templates/qtinstaller/packages/bitmaskvpn/meta/install.js

...emplates/qtinstaller/packages/bitmaskvpn/meta/package.xml

branding/templates/qtinstaller/win-data/readme

gui/providers/providers.json