Added support for the thesis proposal type.

fithesis.dtx

locale/czech.dtx

locale/english.dtx

locale/slovak.dtx

style/mu/econ.dtx

style/mu/fi.dtx

style/mu/fsps.dtx

style/mu/fss.dtx

style/mu/law.dtx

style/mu/med.dtx

style/mu/ped.dtx

style/mu/phil.dtx

style/mu/sci.dtx

test/mu/compare/Makefile

test/mu/compare/expected-fi-proposal-lualatex.pdf

test/mu/compare/expected-fi-proposal-pdflatex.pdf

test/mu/compare/fi-proposal.tex