*in preparation for snapcraft.
- Moving application launch to it's separate file
- Removing "install_after_setup" script because it's redundant with setup.py.
- Fixed issue with xdg-icon-resource not being able to install svg files.
- Better prefix handling in setup.py
- Adding logarithmplotter.svg to import files
- Adding weight for mime-type not to be overloaded by text/plain.
- Using more appropriate properties for desktop files.
Also:
- Fixed reference link in MacOS plist file.
