Overhauled (and moved) libsite

Now that there is a libsh, it makes sense to move libsite there.

Took this opportunity to clean up the long list of messy global
environment variables therein, and thus did the same for each use-case
of these variables.
Cleaned `module/unit': cosmetic, wording

The two sections previously called DYNAMIC and STATIC were irrelevant,
and have hence been renamed to what they actually are: `prime', and
`execute'.

Excess noise removed (too many hash-lines).

General cosmetic clean-up.
Updated `dynamic.csv' for net: closes nima/site#3
Updated `module/util': doc, update

Doc:

    Fixed the usage docstring for `util:secret()'

Update:

    `g_GPG_KEY_PATH' is no more, and site will look for a GPG key
    based on the active profile instead.  No more guess work.
Updated `libexec/softlayer': flag for cache added

Added a programatic flag (variable) to enable/disable caching, and
set that to false as softlayer API calls are not too costly.
Updated `libsite.sh': added `SITE_CORE_BIN'
Updated `module/net': new, fix

New:

    `:net:portpersist' - keep trying for an open port using socat, and
    do so `${attempts}' times.

Fix:

    internal and private functions should not have variable arguments,
    this is the work of the public function; fixed `:net:portping()'.
Amended `bin/ssh': persist on down hosts

If a host is not responding on port 22, then keep trying it until it
does - and only then make an ssh connection attempt.

This is now used in `::remote:tmux()' instead of the ssh binary
itself.
Updated `module/dns': updated `:dns:fqdn()'

This function now tries to determine if the hint supplied is already
a fqdn (by means of known fqdns and `:dns:qialified()'), and if not,
then do it will fall back to the existing logic/code.

This should simplify things for most callers that had to do this work
themselves, and speed things up in the case that the hint supplied was
already an fqdn.
New `module/softlayer'

New site module that interfaces with `extern/softlayer'.
New `unit/static-util.sh'
... module/mongo
... lib/libsh/libsite/unit/dynamic.csv