Add favicon to the validphys page

Created by: Zaharid

This is very clearly the most important missing piece in the whole puzzle.

Add a logo of validphys which has nothing to do with the design (or rather lack thereof) of the report page, but which I have decided that I like (it looks like my terminal window so that is good enough).

Apparently, in order to get it to work for all platforms you have to generate something like this

https://realfavicongenerator.net/

which is what I did.

Also edit the upload script (i.e. the makefile) so it doesn't upload random junk but only the files we are tracking. This was needed because it would upload . with different permissions and cause ssh to fail subsequently.