Add string data structure.
Modify after string data structure testing.
Add vector data structure.
Add record data structure.
Add record set data structure.
Made two changes:

 - Added C-style string concatenation function
 - Made direct constructor function public.
Changed names of field getters and setters.
Remove conflicting typedef for ds_record.
Implement reports with new recordset structure.
Slighty tidy up data structures.
Add hash function to string data structure.
Add string map data structure.
Add hash and compare functions.
Add functionality to string data structure.
Modify config file reading to use ds_str.
Improve names of trim functions.
Improve trim functions.
Add single-point data structures header file.