Catch error when field type change too much

Change-Id: I7904f5e106225b1107c8f9c21a98ff2c0944810e
Add info about steps

Change-Id: Ie40df6db39f31155656e16fc32c2d746630da298
Fix request #6941: errors when list field values are missing

+ Introduce src/utils/tv3_to_test.php to extract data from prod servers as
test cases

Change-Id: I8cc05557841ac042d6009cfe18ccb2f4f2ee0293
Merge commit 'refs/changes/64/2464/8' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  Fix request #6941: errors when list field values are missing
  Add info about steps
  Catch error when field type change too much
This is Tuleap 7.0.99.49

Change-Id: I919bee86839cdcb093997de4f3ec54d156401e46