Adjust and migrate Examples for 7.5

AT:

• it is done
• necessary steps are documented for next time in https://github.com/camunda/camunda-bpm-platform/wiki/Perfoming-a-Minor-Release
• adjust dead links for the "Tasklist Examples" in the overview -> DONE
• merge 7.5 branch to master
• create 7.5 tag

Examples (claim by writing your name behind them):

./bpmn-model-api/generate-jsf-form/README.md => THORBEN
./bpmn-model-api/generate-process-fluent-api/README.md => THORBEN
./bpmn-model-api/parse-bpmn/README.md => THORBEN
./cmmn-model-api/typed-custom-elements/README.md => THORBEN
./cockpit/cockpit-failed-jobs-plugin/README.md -> KRISTIN
./cockpit/cockpit-sample-plugin/README.md -> KRISTIN
./cycle/camunda-cycle-connector-example/README.md -> NOTHING TO DO
./deployment/ejb-pa/README.md => THORBEN
./deployment/embedded-spring-rest/README.md => THORBEN
./deployment/servlet-pa/README.md => THORBEN
./deployment/spring-jboss-non-pa/README.md => THORBEN
./deployment/spring-servlet-pa-jboss/README.md => THORBEN
./dmn-engine/dmn-engine-java-main-method/README.md => THORBEN
./modeler/custom-task-advanced/README.md -> NOTHING TO DO
./modeler/custom-task-simple/README.md -> NOTHING TO DO
./multi-tenancy/schema-isolation/README.md -> KRISTIN
./multi-tenancy/tenant-identifier-embedded/README.md -> KRISTIN
./multi-tenancy/tenant-identifier-shared/README.md -> KRISTIN
./multi-tenancy/tenant-identifier-shared-definitions/README.md -> KRISTIN
./process-engine-plugin/bpmn-parse-listener/README.md => THORBEN
./process-engine-plugin/command-interceptor-blocking/README.md => THORBEN
./process-engine-plugin/custom-history-level/README.md => THORBEN
./README.md
./scripttask/xquery-scripttask/README.md -> KRISTIN
./scripttask/xslt-scripttask/README.md -> KRISTIN
./sdk-js/browser-forms/README.md -> KRISTIN
./sdk-js/browser-forms-angular/README.md -> KRISTIN
./sdk-js/nodejs/README.md -> KRISTIN
./servicetask/rest-service/README.md -> KRISTIN
./servicetask/service-invocation-asynchronous/README.md -> KRISTIN
./servicetask/service-invocation-synchronous/README.md -> KRISTIN
./servicetask/soap-cxf-service/README.md -> KRISTIN
./servicetask/soap-service/README.md -> KRISTIN
./spin/dataformat-configuration/README.md => THORBEN
./startevent/message-start/README.md -> KRISTIN
./usertask/task-assignment-email/README.md -> KRISTIN
./usertask/task-form-embedded/README.md -> KRISTIN
./usertask/task-form-embedded-serialized-java-object/README.md -> KRISTIN
./usertask/task-form-external-jsf/README.md -> KRISTIN
./usertask/task-form-generated/README.md -> KRISTIN
./usertask/task-form-embedded-json/Readme.md -> KRISTIN