common: fix creating symbolic link in Makefile.inc
test: add copyright header to obj_basic.c
Merge pull request #18 from ldorau/test-add-copyright-header-to-obj_basic.c

test: add copyright header to obj_basic.c
Merge pull request #19 from ldorau/common-fix-creating-symbolic-link-in-Makefile.inc

common: fix creating symbolic link in Makefile.inc
obj: add pmemobj_oids_equal()
obj: simple doubly linked list