add a new method is_equal in class Field_blob to compare BLOB field when alter table

- add additional sleep so that we don't get 100% cpu usage retrying saomething that can take some time before succeeding

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.1-single-user

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.0-ndb

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.1-single-user

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.1-single-user

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-5.1-engines

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-5.1-engines

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-5.0-engines

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-5.0-engines

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.1-single-user

into  mysql.com:/home/svoj/devel/mysql/merge/mysql-4.1-engines

into  trift-lap.fambruehe:/MySQL/M51/push-5.1

into  trift-lap.fambruehe:/MySQL/M50/push-5.0

into  trift-lap.fambruehe:/MySQL/M51/push-5.1

into  trift-lap.fambruehe:/MySQL/M50/push-5.0

into  trift-lap.fambruehe:/MySQL/M41/push-4.1

into  trift-lap.fambruehe:/MySQL/M50/push-5.0

into  trift-lap.fambruehe:/MySQL/M51/push-5.1

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.0-ndb

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.1-single-user

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.1-single-user

into  whalegate.ndb.mysql.com:/home/tomas/mysql-5.1-single-user

- put page of deleted row last in list

into  pippilotta.erinye.com:/shared/home/df/mysql/build/mysql-5.1-build

into  perch.ndb.mysql.com:/home/jonas/src/mysql-5.1-new-ndb

into  perch.ndb.mysql.com:/home/jonas/src/mysql-5.1-new-ndb

clean up varsize
by putting varpart ref "inside" fixpart instead of "optionally" at the end

into  pippilotta.erinye.com:/shared/home/df/mysql/build/mysql-5.1-build

```yaml
Merge pippilotta.erinye.com:/shared/home/df/mysql/build/mysql-5.0-build-work-vanilla-building
into  pippilotta.erinye.com:/shared/home/df/mysql/build/mysql-5.1-build-work-vanilla-building
```

Fix test cases to pass for a plain ./configure && make build. This includes disabling two test cases when certain features are not present in the server. We're not losing coverage from this because these features are usually present, and disabling them here only serves the purpose to make the test cases work in the unlikely case that they aren't.
---
fixes

into  ymer.(none):/usr/local/mysql/mysql-5.0-ndb

into  ymer.(none):/usr/local/mysql/mysql-5.1-telco-gca