Unhelpful error message when no stevedore plugins load

[Steve Baker]

When heat is installed incorrectly and no plugins get registered with stevedore, the first indication that something is wrong is when a stack is created and the user gets this message:

ERROR: The template version is invalid: Template version was not provided

heat-engine should check that at least one template parser is registered on startup, then log an error and exit.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/141847

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/141847
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=ed76af426934147b895e2b746193491896369f82
Submitter: Jenkins
Branch: master

commit ed76af426934147b895e2b746193491896369f82
Author: Tetiana Lashchova <email address hidden>
Date: Mon Dec 15 18:55:39 2014 +0200

    Check that template format plugins are registered

    Otherwise log an error and exit

    Change-Id: I2beb33371cf5e6701e22dbb41c8f5aa681c379de
    Closes-Bug: #1402426

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/juno
Review: https://review.openstack.org/148870

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/148870
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=65294f43977bb3bbf0cb67a321cbff3ab5039e35
Submitter: Jenkins
Branch: stable/juno

commit 65294f43977bb3bbf0cb67a321cbff3ab5039e35
Author: Tetiana Lashchova <email address hidden>
Date: Mon Dec 15 18:55:39 2014 +0200

    Check that template format plugins are registered

    Otherwise log an error and exit

    Change-Id: I2beb33371cf5e6701e22dbb41c8f5aa681c379de
    Closes-Bug: #1402426
    (cherry picked from commit ed76af426934147b895e2b746193491896369f82)