localeTest: fix build.
ICUTest: style and output formatting fixes
localeTest: fix corrupted characters.

This file used to hold iso-8859-15 encoded bytes for testing our char
conversion ability. However something went wrong and they all got
replaced by unicode "invalid character" mark. Use \x notation to escape
the actual bytes we want to test.
Convert BUnicodeChar tests to cppunit.
Convert collator test to cppunit.
Convert language tests to cppunit.