Bug#17261 Passing a variable from a stored procedure to UDF crashes mysqld

- Update of test toolsand Makefiles to make it possible to test always test udf's as part 
of the mysql test suite


mysql-test/mysql-test-run.pl:
  Add the path where mysqld will udf_example.so used by the udf test
mysql-test/r/udf.result:
  Update test results
mysql-test/t/udf.test:
  Update tests
  The "--error 0" directives should actually be changed to the correct error number returned but that error  number is lost. W e do however get the right error message and that is checked in 
  the .result file.
sql/Makefile.am:
  Build shared library udf_example.so
sql/share/errmsg.txt:
  Update the max length of %s string from 64 to 128
sql/sql_udf.cc:
  Add DBUG_PRINT just before dl_open
sql/udf_example.cc:
  Use isalpha instade of my_isalpha

sql/sql_udf.cc

@@ -432,6 +432,7 @@ int mysql_create_function(THD *thd,udf_func *udf)
   }
   if (!(dl = find_udf_dl(udf->dl)))
   {
+    DBUG_PRINT("info", ("Calling dlopen, udf->dl: %s", udf->dl));
     if (!(dl = dlopen(udf->dl, RTLD_NOW)))
     {
       DBUG_PRINT("error",("dlopen of %s failed, error: %d (%s)",