BibField: backported improvements from pu
- Major update of BibField module with some speed improvements and enhancements from pu branch.
- New functional test to verify that the speed of recjson is below two times of that of recstruct. (closes #1687)
Signed-off-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
Tested-by: Tibor Simko <tibor.simko@cern.ch>