Add build option to skip Cypher module

If -DskipCypher is given on the command line all the Cypher related build will be skipped
Updates changelogs for 2.1.5
Merge pull request #3131 from davidegrohmann/2.1-skip-cypher

[2.1] Add build option to skip Cypher module
Merge remote-tracking branch 'upstream/2.1-maint'