Valid names in ontology entities (classes, relations, diagrams, etc.)

[pedropaulofb]

The files' names must contain only valid characters for Windows and Linux directory paths. The Visual Paradigm allows the creation of diagrams with invalid characters, like ":" - in this case, the generated image is going to have an invalid path name. The substitution has impact on the VPP, JSON, PNGs and TTL files (specific and general for this last one).