Description of problem:
Openshift trims the buildconfig name for very long input, but the build cannot be started as '-build' is appended at the end.

Version-Release number of selected component (if applicable):
Openshift Dedicated
oc v3.1.1.6-33-g81eabcc
kubernetes v1.1.0-origin-1107-g4c8e6f4

How reproducible:
Always

Steps to Reproduce:
1. Create a buildconfig with a really long name, exceeding 64 chars
2. Start a build

Actual results:
Pod creation may fail:
oc describe builds jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1                                                                                         Name:			jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1
Created:		21 minutes ago
Labels:			buildconfig=jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe,is_autorebuild=false,openshift.io/build-config.name=jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe
Annotations:		openshift.io/build.number=1
Build Config:		jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe
Duration:		0
Build Pod:		jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1-build
Strategy:		Custom
URL:			git://pkgs.devel.redhat.com/rpms/jboss-webserver-3-docker
Ref:			4c251dccbe023735a4f9df226125568968b53745
Image Reference:	DockerImage brew-pulp-docker01.web.prod.ext.phx2.redhat.com:8888/rcm/buildroot:eng-rhel-7-candidate-20160413130433
Expose Docker Socket:	yes
Environment:		DOCK_PLUGINS={"prebuild_plugins": [{"args": {"parent_registry_insecure": true, "parent_registry": "brew-pulp-docker01.web.qa.ext.phx1.redhat.com:8888"}, "name": "pull_base_image"}, {"args": {"labels": {"Authoritative_Registry": "registry.access.redhat.com", "distribution-scope": "public", "Vendor": "Red Hat, Inc.", "Build_Host": "osbs-devops.openshift.com"}}, "name": "add_labels_in_dockerfile"}, {"name": "change_from_in_dockerfile"}, {"name": "add_dockerfile"}, {"args": {"command": "rhpkg sources"}, "name": "distgit_fetch_artefacts"}, {"args": {"repourls": ["http://git.engineering.redhat.com/git/users/vrutkovs/openshift-jenkins-docker/plain/aos-signed-latest.repo"]}, "name": "add_yum_repo_by_url"}, {"name": "inject_yum_repo"}, {"name": "dockerfile_content"}], "exit_plugins": [{"args": {"url": "https://api.devops-osbs.openshift.com/", "verify_ssl": false, "use_auth": true}, "name": "store_metadata_in_osv3"}, {"args": {"kojihub": "https://brewhub.stage.engineering.redhat.com/brewhub", "url": "https://api.devops-osbs.openshift.com/", "blocksize": 10485760, "koji_ssl_certs": "/var/run/secrets/atomic-reactor/kojisecret", "verify_ssl": false, "use_auth": true}, "name": "koji_promote"}, {"name": "remove_built_image"}], "postbuild_plugins": [{"args": {"load_exported_image": true, "method": "gzip"}, "name": "compress"}, {"name": "tag_by_labels"}, {"args": {"registries": {}}, "name": "tag_and_push"}, {"args": {"pulp_secret_path": "/var/run/secrets/atomic-reactor/pulpsecret", "load_exported_image": true, "dockpulp_loglevel": "INFO", "pulp_registry_name": "brew-qa"}, "name": "pulp_push"}, {"args": {"image_id": "BUILT_IMAGE_ID"}, "name": "all_rpm_packages"}], "prepublish_plugins": [{"args": {"remove_former_image": false, "dont_load": true}, "name": "squash"}]}
:			OPENSHIFT_CUSTOM_BUILD_BASE_IMAGE=brew-pulp-docker01.web.prod.ext.phx2.redhat.com:8888/rcm/buildroot:eng-rhel-7-candidate-20160413130433
Output to:		DockerImage root/vrutkovs-httpd:ce-1.2-tomcat7-webserver-3.0-jdk-8-rhel-7-docker-candidate-20160415103634
Status:			Cancelled (Failed to create build pod: Pod "jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1-build" is invalid: metadata.labels: invalid value 'jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1', Details: must have at most 63 characters, matching regex (([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?: e.g. "MyValue" or "".)
Events:
  FirstSeen	LastSeen	Count	From			SubobjectPath	Reason			Message
  ─────────	────────	─────	────			─────────────	──────			───────
  21m		21m		1	{build-controller }			HandleBuildError	Build has error: failed to create build pod: Pod "jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1-build" is invalid: metadata.labels: invalid value 'jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1', Details: must have at most 63 characters, matching regex (([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?: e.g. "MyValue" or ""
  21m		13m		458	{build-controller }			FailedCreate		Error creating: Pod "jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1-build" is invalid: metadata.labels: invalid value 'jboss-webserver-3-docker-ce-1.2-tomcat7-webserver-3.0-jdk-8-rhe-1', Details: must have at most 63 characters, matching regex (([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?: e.g. "MyValue" or ""


Expected results:
Pod name is trimmed correctly, the build can start

Additional info: