This patch changes the main name of 3 byte character set from utf8 to
utf8mb3. New old_mode UTF8_IS_UTF8MB3 is added and set TRUE by default,
so that utf8 would mean utf8mb3. If not set, utf8 would mean utf8mb4.
Details:
- Limit the queries to character sets and collations
which are most probably available in all build types.
But try to preserve the intention of the tests.
- Remove the variants adjusted to some build types.
Note:
1. The results of the review by Bar are included.
2. I am not able to check the correctness of this patch
on any existing build type and any MySQL version.
So it could happen that the new test fails somewhere.
