Update AX_BOOST_BASE autoconf macro to serial 23
.gitignore: add Source/TAGS
Octave: ignore generated files
Octave: remove Python code from std_carray.i
Octave: whitespace/indentation cleanup of octave.cxx
Octave: use common example.mk for examples, patterned after javascript
Octave: remove deprecated -global/-noglobal command-line arguments
DO NOT PUSH: only run Travis Octave tests
Octave: cleanup/restructure library code