gnc-euro: non-ISO-symbols in gnc_euro_rate_struct gnc_euro_rates

[Frank H. Ellenberger]

Hi Herbert,

I am just adding EEK to the list and wondering about a bunch of 
non-ISO-symbols there like "S" and "SCH" for "ATS". Could you explain me the 
intension? 

Special, if we extend the list for other frozen rates, I fear we will get 
collisions.

TIA
Frank