Directory support/pydocstrip

Please visit
    http://docstrip.sarovar.org/
for the full description on `docstrip.py`.

docstrip.py

* is the Python version of TeX's `docstrip` utility
* but it use KINS files instead of TeX's INS file.

* some advance functions of `docstrip.py`:
  ----------------------------------------

  a) Support the switches at the command line, for e.g,
        docstrip.py -e "test=0;foo=1"
     or
        docstrip.py -e "test=1;foo=1"

     With this features,
     we can easily create a quite sophisticated generation.

  b) Support the source-file-time checking:

     If the (DTX) source file havenot changes, the `docstrip.py`
     knows this and skips the generation. So if we have many DTX
     files, or the DTX files have quite big size, we may save
     very much time of generation.

     (The behavior can be overwritten by using `--force` option.)

  c) Can generate only files whose names match a regular expression:
     for example:
         docstrip.py [...] -g "foo[0-9]\.tex"
     will generate "foo1.tex", "foo2.tex" but "foo100.tex"

  d) Can run in DEBUG mode:

     The DEBUG mode is turned on by the `--debug` option.
     No file is generated; but we will know what `docstrip.py`
     would do in the real mode.