Added helper structs and functions for descriptor storage
fixed syntax error
Added define for control descriptor value details maximum length
Added helper function to read the file header into cached location
Remove duplicate doxgen comments. Added placeholder for function to read header from storage header.
Refactored logging to allow different backends. jdksavdecc_log_file_init() for logging to FILE, jdksavdecc_log_aecp_init() for logging via SET_CONTROL unsolicited responses of a UTF8 format control, via a frame_sender.