Behaviour introduced in MNT-14924 should be user configurable between current behaviour and prior Alfresco version behaviour

[Technical description of the issue]
With the changes introduced in MNT-14924 new versions of file take the filename (and mimetype) of the most recent uploaded file which is undesired behaviour for some customers.

[Current behaviour]
Described in MNT-14924

[Desired behaviour]
When there are changes in the extension at upload, it seems a good action to take this change in account for mimetype change and for transformation.
I understand also it can be good to reflect the filename changes, but not for all customers.
For [customer] the behavior before upgrading was that documents were not renamed when uploading new versions, and now documents are renamed. At [customer] this name change are not for extension change (no mimetype change).

We can imagine a simple parameter in alfresco-global.properties used to determine if the document must be renamed when filename change or not. This way the customer decide which behavior he wants to apply. By default, the document would be renamed (current behavior in 5.2 version) but it is possible to go back to previous behavior if the parameter is set to do so.

[Notes]

Related to: MNT-14924
Submitted by: Partner