Fix to register all projects and register an additional gearman function for each project.

Jenkins.getProjects() wasn't returning maven and multi-config projects.
This change now attempts to register all projects.  The only caveat
is that the multi-config projects don't get registered quite right
because the labels are treated differently in that project.  I don't
plan to fix multi-config project registration because openstack
doesn't have any of those projects setup in jenkins.

Register an additional function for each executor worker.  We register
a generic "build:$projectName" function on each executor
that can run a build on $projectName.

Minor change, set gearman-plugin version to 'SNAPSHOT'.  The maven
release plugin will convert to a non-SNAPSHOT version on release.

Change-Id: I49a0f73d297e61657fb6f31f26e87c181a644115