WIP
BS-2402, check version

and allow to choose source/target version
BS-2402, count time only from beginning of migration
BS-2402, enhance logs
BS-2437, remove trace of .bat script + rename them
BS-2436, add more warning and clean logs
Merge branch 'master' into improvement

Conflicts:
	bonita-migration-distrib/src/main/groovy/org/bonitasoft/migration/core/MigrationRunner.groovy
	bonita-migration-distrib/src/main/resources/versions/6.0.2-6.1.0/Bonita-home/MigrateFeature.groovy
Merge branch 'master' into improvement
fix missing methods
BS-2436, print if we replace or merge target file when we migrate bonita home
Merge branch 'improvement'