Moved test program to t subdirectory.

diff --git a/standalone.c b/t/standalone.c
similarity index 100%
rename from standalone.c
rename to t/standalone.c

diff --git a/utf8-locale.c b/t/utf8-locale.c
similarity index 100%
rename from utf8-locale.c
rename to t/utf8-locale.c

diff --git a/utf8-locale.h b/t/utf8-locale.h
similarity index 100%
rename from utf8-locale.h
rename to t/utf8-locale.h