add Init_Bithrtree() & Create_Bithrtree() functions
try another Create_Bithrtree() function
unfinished the binary thread tree can not understand
add tree_node struct and ptree struct
add queue header file
Add Init_Queue() & Enqueue() & Dequeue() & Print_Queue() functions
add queue test file
update the parent_mode header file
fix queue bugs
add Init_Ptree() & Create_Ptree() functions
test Init_Ptree() and Create_Ptree() functions
update makefile to create ptree_test elf file
add Ptree_Empty() & Ptree_Depth() functions
Add some functions:

Root() & Value() & Assign()
Parent() & Leftchild() & Rightsibling() & Print_Ptree()
fix some bugs and add Print_Tree() & Traverse() functions
add test file to test the parent tree
add elf file
add child mode header file
add queue header file
add queue c file