Preparing to purge profiles

Also removed some old junk.
Moved from libexec/core to libexec/
Restructure: modules moved for segregation work

All modules from `lib/core/*' have moved to a new directory called `module'

The one file in `lib/core' which was not even a module (called `site')
has now moved to `lib/libsite'.
Retro `lib/libsite': segregation, new user profile

This retrospective fix is as part of the module segregation fix, not
only has this file been moved (used to be `lib/core/site'), but it now
presents new *_MOD_* variables - an area specifically for site
modules, not under `lib/'.

Fixed minimum requirements for new user profiles.
Added example site.conf for new user profiles
Overhauls: segregation and extern

Segregation:

    Work to split up modules, to allow internal business logic to
    be easily seperatable from the core site code.

    This work's focus is to change the structure of the code, to
    separate site-specific code from external configuration data.

    The result is that site can finally move into github as it
    contains no business data, and users can then use a separate
    repository for managing their site's configuration data.  The
    `profile/' directory is provided for this purpose (and is thus
    in `.gitignore').

Extern:

    Overhauled how `extern' builds are carried out.

    This is now much cleaner, with a proper install and uninstall;
    at both makefile levels.
New `lib/libpy/libsite': site python module

New:

    lib/libpy/libsite:

        This new python module is for site; even though site is in
        general all about bash, at times it relies on higher level
        functionality from other languages, and for python, this
        is where that extra functionality is coded.

    libexec/ssh:

        Moved out python secret function into new site python module,
        and updated it to use the new site module.

    lib/libsite:

        The core bash lib file has been made aware of the new new python
        site environment.

    .gitignore:

        Updated to ignore `*.pyo' and `*.pyc' files.
Cleaned up the `share' directory
No need for etc/ in core

The bash completion file moved to share/, and the redundant
configuration file (which was never a configuration file) was simply
merged into `lib/libsite'.
REAME magic

The new README.md in the master (and any other non-gh-pages) branch now
simply refers to the README.md in the gh-branch.

The installer generates a README.md for conveneience by checking out
of the gh-pages branch.