feature: Support for master thesis

[at15]

There are a few students doing master thesis, the requirement for format is same as phd thesis except the cover page. Ref ucsc guideline.

Currently the template can only switch between proposal and phd thesis, is it possible to add extra config in the document class for master thesis? I can make a PR after I got all the signatures (the hardest part in thesis ...), currently I change the text in template directly.

required changes

• \dissertationname{} and \Dissertationname{}
• dissertation -> thesis, master thesis don't need disseration