Merge pull request #33 from fptudelft/content

material for Week 4 - Higher order functions
It really irks me when people forget to capitalize Alonzo Church's last name.
Fixed some more typos.
Merge pull request #34 from pbl64k/hof-srt

Fixed some minor typos in HOF section subtitles.
Merge pull request #35 from fptudelft/content

slides + transcripts for week 5
Several minor changes to subtitles in the monad/interactive series of lectures.
Merge pull request #36 from pbl64k/monad-srt

Several minor changes to subtitles
material for chapter 9 and 10