ncm mysql: fix processing of tableOptions + misc. cleanups

I would like to add unit tests... wait before merging.

Tested at GRIF. Note that the `ALTER` command used to implement `tableOptions` can take some time...
Normally the value must not be quoted. If you look at MySQL `ALTER TABLE` command, you will see that the value is always a word or space-separated list of word. Not that the current implementation allows for a non existent value (empty string) and that for many options it is the same to put the whole option including its value as part of `$option` or to put the keyword part in `$option` and the value in `$value`. In the latter case, the option must accept an `=` sign between the option name and the value.