TRQ-1054: implement function set_str_csv for parsing attr CHECKPOINT_DEFAULTS
TRQ-1054: added unit test for set_str_scv

- fix memory leak in remove_csv_item
- implemented unit test for set_str_csv
TRQ-1054: fix processing operations '+=' and '-=' with list of parameters
TRQ-1054: implement estention in unit test for set_str_csv()

- remove stubs of csv_* functions from scanffolding
- add source Libcsv/csv.c to several Makefiles in unit tests
- implement extentsion in unit test for testing set_str_csv()

Conflicts:

	src/server/test/job_recov/Makefile.am
	src/server/test/job_recov/scaffolding.c
TRQ-1054: fixes after code review

- add comments
- check coding standard
TRQ-1054. Fix a compilation error.