New @id generation for parsers and other bug corrections

[bclenet]

This PR addresses the following topics:

• Closes [Bug]: RRID should be replaced by AltIdentifier #137, closes [Bug]: RRID of SPM is used for all software in the examples #138 about RRIDs of Software records
• new strategies for @id generation :
  • for Agents, @id is set to the value of Label + a random alphanumeric string
  • for Activities, @id is set to the value of Label + a random alphanumeric string
  • for Entities, @id is set using the value of AtLocation to generate a bids: id. It is set to an uuri if AtLocation is not set or not suitable for an urn value
• launcher for nidm examples makes BIDS compliant paths for files that are part of BIDS dataset, or derivatives
• correction of some function descriptions for AFNI and FSL
• some other unreferenced bugs for all parsers

[cmaumet]

Discussed with @bclenet, this is ready to review