Grizzled-python

* Added `grizzled.sys` module, with `python_version()`,
`python_version_string()`, `split_python_version()` and
`ensure_version()` functions.
* Added `grizzled.file.universal_path()` and `grizzled.file.native_path()`.
A universal path always uses a '/' as the file separator, no matter what
the underlying operating system uses. A native path uses the underlying
operating system's path separator. These two functions convert between the
two notations.
* Fixed bug in `grizzled.file.eglob()` stemming from camel case conversion.
* Added `grizzled.os.file_separator()` function.
* Changed `grizzled.os.get_path_separator()` to `grizzled.os.path_separator()`.

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* Converted public functions, methods, parameters and variables that use
camel case names to names that are more consistent with standard Python
naming conventions. Existing camel case functions are still in the API,
but are deprecated. Calling them will result in a runtime warning.

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* Created `grizzled.io.filelock` module, with a `FileLock` class that
provides a portable file locking interface.
* Added `grizzled.file.eglob()` function.
* Added `grizzled.os.withDirectory()`, a context manager for the `with`
statement.
* Added `grizzled.io.PushbackFile` class
* Added `grizzled.file.copyRecursively()` function
* Moved `CommandLineParser` from `grizzled.optparse` to `grizzled.cmdline`
* Augmented `CommandLineParser` to permit specifying an epilogue to be printed
at the end of the usage message.
* Added `grizzled.net.download()` function
* Added `grizzled.io.Zip` class

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* Initial version posted to the web.