fixed struct name in child_list
fixed list and simplified list_add
trie node something... I have no idea
callback and handle token
words are inserted in trie
implemented syntax tree validation
forward declared parse_tree_struct and validate_tree() in trie header
called validate_trie() for every syntax tree in trie
added UDID on parse_tree structure
implemented reset_parse_tree()
UDID is set to validate_tree callback