adding some tests in testsuite

(sorry for the mess, trouble with Github or my browser)

adding missing files in LIST
revamp of all test_obj_* tests
test_size now tests size of structures, and also content of SIZE(value,/struct) (bugs for HASH() & LIST(), see #1807
format c() for time is not well supported (I have to do the bug report)
correcting calendar.cpp to restore the generic format c() (test added in new test_format.pro
removing a space in TOC output

gnudatalanguage / gdl