- can aid when creating source-only or binary-only packages

Set the m4 -I include accordingly to have the folllowing:
  - the directory of the parser.
  - include/ in the top-level source tree of the current target
    (eg, src/finiteVolume/include-m4/ when compiling libfiniteVolume)
  - include/ from OpenFOAM

Additional -dry-run option for makeParser, wrap-lemon for expanding m4
only.

Extend m4 wrapping support to include bison as well.

- include ragel and lemon

- rename pre-generated files to ".cc" so that they are more
  recognizable as being different from regular file content.

- 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

- minor cleanup of wmake sources

This reverts commit c5bea524.

This reverts commit 2e1e671d.

- more consistent script names
- remove '-help' option from internal scripts

- place wmkdep and dirToString executables under
  utilbin/$(WM_ARCH)$(WM_COMPILER).
  This helps somewhat when copying rules about, and might help when creating
  general rules.

  - match comments to names of scripts
  - remove comments about using C-shell (not true anymore)
  - use 'assert' style syntax in places instead of if/then/fi
  - wcleanMachine supports multiple arguments