[forms] closes #2437859 - Detect and prevent concurrent edition of the same entity. Add the timestamp of form generation to each entity's meta-information fields. On form validation, check that no concurrent change is overwritten and raises a ValidationError in case of concurrent change. A nicer handling with a message and a link to the new version of the entity would be a good thing...

[MESSAGES CONTROL]
disable-msg = C0301

[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name

[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$

[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception