Korean charset collator can't be built from ko_charset.txt because of

"The runtime code decomposes Hangul syllables on the fly, with recursive
processing but without making the Jamo pieces visible for matching. It
does not work with certain types of contextual mappings."
"While handling a Hangul syllable, contractions starting with Jamo L or
V would not see the following Jamo of that syllable." (this is where we
bail out already with the first syllable of ko_charset.txt)
Another condition to fail is described as "A contraction ending with
Jamo L or L+V would require generating Hangul syllables in
addTailComposites() (588 for a Jamo L), or decomposing a following
Hangul syllable on the fly, during contraction matching."

Excluded the file from the build for ICU >=53 and hope that ICU in the
mean time handles Korean collation correctly.

Additionally, ICU 53 took ages (if it would had finished at all) to
build the collator from zh_TW_charset.txt because of the \u#### escaped
notation. Converted the file's content to characters using
http://www.rishida.net/tools/conversion/

Change-Id: I6520a362b94428eac42085e2740aee2c468ed693
Reviewed-on: https://gerrit.libreoffice.org/9205Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>