fix surrogate handling in set_scratchpad_codepoints_from_text()
fix surrogate handling in set_scratchpad_codepoints_from_text()

- was assuming all character codes >= 0xD800 were part of a surrogate pair
  and skipping the following char

- this assumption was wrong for characters in the 0xE000-0xFFFF range

grantm/ucf,grantm/ucf,grantm/ucf