Octave: simplify Examples/octave/example.mk
Octave: cleanup/restructure library files

- Restructure runtime code into declarations, function
  and class definitions, and initialisation code
- Rename internal functions/types to follow SWIG_Octave...
  or SwigOct... naming styles
- Style/comment/whitespace cleanups
Octave: whitespace/style cleanup of Doc/Manual/Octave.html
Octave: drop support for Octave versions older than 3.2.0

- Latest non-supported version is 3.0.5, released 2009-04-09
- Earliest supported version is 3.2.0, released 2009-06-05