textproc/tth: Update 4.03 => 4.16, take maintainership

• Use actual MASTER_SITES and WWW
• Specify LICENSE and LICENSE_FILE
• Install all the *.sty and babel files under ${DATADIR}
• Simplify Makefile
• Make DOCS option really work
• Pet portclippy(1) and portfmt(1)

Approved by: yuri@ (Mentor)
Differential Revision: https://reviews.freebsd.org/D53571