Rename legal.txt to LEGAL.txt

Author: Cube

legal.txt renamed to LEGAL.txt

@@ -350,4 +350,4 @@ Leptonica
  -  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  -  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *====================================================================*/
-===================================================================================
+===================================================================================