ENH: make it easier to switch between the various make dependencies programs.
- However, the new ragel-based parser is much faster than the others, and does not cause 'too many open files' error that the flex-based parser does (issue #784). The timings (using src/sampling as being somewhat representative) $ wclean; wmakeLnInclude -u .; time wmake -s dep 3.4s wmkdepend (ragel) [now default] 5.7s wmkdep (flex) 6.1s cpp -M - The makeDepend script is for testing purposes only, but could used as a hook for other dependency generation systems (eg, ninja). It simply wraps 'cpp -M' in a form that is calling compatible with wmkdepend. BUG: wmkdepend parser was missing optional leading space on #include match STYLE: use -G2 (goto-based) option for wmkdepend state machine - the machine is compact with few states and lends itself to this