v0.3.1-alpha

Fixes compilation so that it compiles on oldest supported version of Ubuntu. First distrbuted version. Plenty of errors and problems, I'll point out some notable ones:

When installing software, the online repo rarely works. Planning to change to appimagehub to fix this.
If you launch appimage directory from the directory it will not be sandboxed. Launching from desktop file or from path will work though.
Will not use system icons.
Inputting a file path sometimes doesn't work. Ex. "sudo nep install ~/Downloads/example.AppImage" will most likely not work.

Please report any issues that arise when using this alpha version.
Run "sudo ./Neptune-x86_64.AppImage --install" to install Neptune.