Add bash commands for sorting triples

[thiviyanT]

Carried out the proposed change, @samuell . Please review it and ensure the instructions are clear.

Cheers,
Thiviyan

[samuell]

@ThiviyanThanapalasingam Ah sorry, I was perhaps not so clear in the issue: The functionality to assume sorted input in order to make rdf2smw faster is not actually implemented. The issue was just to remind that such an improvement could be done ... perhaps as an alternative behaviour, that could be changed with a flag, such as rdf2smw -assume-sorted or similar. Sorry for the confusion!

[thiviyanT]

It seems that there was some misunderstanding on both ends, @samuell. I was under the impression that the -assume-sorted option was defaulted to true because the semantic mediawiki pages that I obtained using rdf2smw were quite incomplete (i.e. the pages were not displaying certain triples). By analysing the rdf2smw output xml files, I found out that this was a cause of the triples not being organised by subjects and predicates in the input files. I read the issue you raised and thought it was relevant to the problem that I was having. I think it would be best if I raise a separate issue, later, and explain this in detail.