Private dataset name change

[marcomass]

Enable the user to change the name of his/her datasets

[marcomass]

dataset renaming produces wrong schema result: in the schema of the renamed dataset the 4 coordinate attributes are replicated (for any renaming), both for GTF and tab-delimited GDM format.

[akaitoua]

@marcomass I fixed the bug by making a modification on GMQL package. GMQL package needs to be rebuilt and loaded again for the effect of the fix to be noticed.

[marcomass]

@akaitoua
The issue is fixed, thanks!
Yet, the attribute strand of type char in the original dataset is changed to string in the renamed dataset; could it be fixed also this minor?

Anyway, could you please add some comments in the code to explain the changes you made to resolve the problem?
It will help if in future anybody needs to change something in that part of the code.