chore(version): update pom, maven dependency and download button to 7.1

related to #CAM-2081
chore(downloads): add 7.1.0.Final

related to #CAM-2067
chore(getstarted): maven formatting & central
updt(users): add s-kreditpartner to reference user
updt(users): add logo for s-kreditpartner
feat(get-started): add java ee getting started tutorial

related to #CAM-1450
chore(gs/jee6): improve source download

making source download more visible

related to #CAM-1450
chore(gs/jee): fix typo

related to #CAM-1450
chore(gs/javaee): improve download hint
impr(get-started): add source code links for get started guide

related to #CAM-2102
chore(get-started): adjust initial github/source code box

related to #CAM-1450 and #CAM-2102
chore(gs/spring): add source code links for spring get started guide

related to #CAM-2103
chore(download): add modeler standalone 1.1.0
updt(roadmap): adjust after 7.1 release
updt(bpmn.tutorial): add link to bpmn forum
updt(bpmn.examples): fix typos