Improve man page formatting slightly

Improve man page formatting slightly

- Don't add extra space whenever [TT]/[BB]/[II] is specified.  This may
  have been necessary 15 years ago, or has always been broken, but
  currently it adds a lot of forced double spaces and leading spaces
  onto man pages.  The text is much more readable without it.
- Merge all command line options into a single OPTIONS section. Divide
  it into groups using extra paragraphs in between.  Could possibly be
  formatted nicer, but that would require extra nroff trickery that we
  might rather get rid of.

Related to #1437.

Change-Id: I4b27b79604a1830914cd5d14d6581918f33bb107