Better (UTF8) encoding support for CSV import

[rufuspollock]

Webstore fails on attempt to import this csv file:

Entity,Currency,Alphabetic Code,Numeric Code,Minor unit,Withdrawal Date,Remark
AFGHANISTAN,Afghani,AFN,971,2
ÅLAND ISLANDS,Euro,EUR,978,2
ALBANIA,Lek,ALL,008,2

But succeeds on (A on Aland Islands has been un-accented):

Entity,Currency,Alphabetic Code,Numeric Code,Minor unit,Withdrawal Date,Remark
AFGHANISTAN,Afghani,AFN,971,2
ALAND ISLANDS,Euro,EUR,978,2
ALBANIA,Lek,ALL,008,2