add dbsglinked library to the project
include glinked_list.h to access library functions
include stdbool.h so helper functions can use bool
include string.h
add helper functions
* nickname_cmp to pass to lib functions for nick comparison
* sstrdup to duplicate strings
* print_name a function that helps displaying xfn_list contents
add XFN_ADD, XFN_RM, XFN_LIST commands
add xfn_add_handler_cb boilerplate
add xfn_rm_handler_cb boilerplate
add xfn_list_handler_cb and implementation
add glinked_list.c and glinked_list.h to project
add glinked_list.c to build.sh