added support for "expected to throw". updated tests.

 * EVLibTest_Test_EndCommon(): fixed filler string not being aligned
    (when the results do not have the right length);
 * EVLibTest_Do_Check(): added support for flag 't'
    (expression/code is expected to throw an exception);
 * EVLibTest_Do_Batch(): added support for 'code.throws' option
    (mapped to EVLibTest_Do_Check() 't' flag);
 * test/vimrc_00_selftest-local.vim: added testing code for new
    "expected to throw" option/flag;