Eliminate redundancy and/or simplify default case for compiling unittest_data.h about cld2 HOT 4 OPEN

unittest_data.h has two copies of all the data, one in UTF-8 encoding and one 
in standard C-string hex escape sequences.

The UTF-8 encoded data is often easier for humans to read. For compilers that 
do not support UTF-8 strings, compile with
  -Davoid_utf8_string_constants

Did I miss something here, or did you fail to read the comments at the front of 
unittest_data.h ? /dick

I missed the comment at the top of the file. Thanks.

Devil's advocate question:
Given that -Davoid_utf8_string_constants should work on all compilers while the 
default (without the define) might break, and that the stated reason for the 
UTF-8 is for human readability, why not just turn all the UTF-8 strings into 
single-line comments and be done with it? Alternatively, why not invert the 
#ifdef logic? There doesn't seem to be an obvious reason to have both copies of 
the data at all.

OTOH, we could use the redundant copy to verify that indeed your compiler did 
compile the UTF-8 text correctly, i.e. that there is a perfect binary match 
between both copies of the string.

My vote would be to invert the ifdef so that the default case works everywhere.

I'll set this back to assigned for now, but change defect to enhancement since 
and priority to low since it is working as intended :)