update color, add fakulty logo, add option to use different color than tugreen

[The-Ludwig]

We might want to make it easier for people to choose a different color than tu-green. Maybe we get a little more variety in the look and feel of theses.
tucolor is now replaced with color with the added option to specify a different one with e.g. color=pink. For that the kvoptions package is used.

Also the TU green in the logo and in the document was not the tu recommendet #83b818, so I updated it.

I also added the faculty logo to the title page, which you might not like, so feel free to suggest a better option or revert it back to the way it was. I think we should keep the logo in the repository anyways, so people have a fast way to use it.

[maxnoe]

A general comment: it would be much nicer and easier to review such unrelated changes in single PRs.

We might want to make it easier for people to choose a different color than tu-green.

I really don't see why we should offer that option, given this is the tudothesis. Nobody prevents you from actually changing the source code if you want to use this for something else or chose a different color.

Also the TU green in the logo and in the document was not the tu recommendet #83b818, so I updated it.

This is a problem with most PDF viewers (especially on linux) not respecting the CMYK color profile in that file... I thought I had replaced all CMYK logo pdfs in my repos with the correct RGB version, seems I missed it here.
Fixed on the master now.

I also added the faculty logo to the title page, which you might not like, so feel free to suggest a better option or revert it back to the way it was. I think we should keep the logo in the repository anyways, so people have a fast way to use it.

That's part of the thesis.tex file, the part that users are expected to change anyways, so all fine.

Since I don't like the color change and I fixed the logo on master (which I am about to rename to main...), I'll close this PR, please go ahead and open one with only the department logo.