- Moving detection of the MY_CS_CSSORT, MY_CS_PUREASCII, MY_CS_NONASCII
  flags of loadable collations from add_collation() in mysys.c
  to my_cset_init_8bit() and my_coll_init_simple() in ctype-simple.c.

- Adding tests that these flags are set properly for loadable collations

- Moving LDML test related *.xml files from mysql-test/std_data/
  to mysql-test/std_data/ldml/, as there will be more *.xml test files