Updated `libsite.sh': new, fix, cleanup

New:

    New `core:imported()' function to check if a previous
    `core:softimport()' on a fiven module was successful or not.

    The deadman touch-file now contains the traceback to aid
    troubleshooting.

    `Makefile' updated with the ${SITE_SCM} path again, with a
    symbolic link that points to it from `~/.site/.scm'; mostly for
    unit-testing.
Updated `module/git': closes nima/site#9
Updated `module/unit': fix, cosmetic

Fixed a small reporting issue.
Updated `module/hgd': graceful degredation
Unit test `hgd' updated
Updated `module/util': encapsulated `jsontool'
Unit test for `util' updated
Updated `module/cpf': added `HAS_AUTOED' theme option
... module/gpg
... module/net
Updated `module/vault': new, clean

The public `read()' function was split up into public and internal.

Unit test for the new private function added.

Cosmetic rearrangement of code.
New `module/mongo'
New `module/softlayer'

New site module that interfaces with `extern/softlayer'.
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.
New `module/pagerduty': pagerduty module
Updated `travis'

Moved some package installs into the specific module requiring it in
order to reduce the shared build commands, thus speeding up all
builds as a result.
Updated `module/remote': ldap dependency removed

This module no longer (directly at least) depends on the ldap module.