WL#390: Options for better dump control for MySQLDUMP

Currently MySQL misses some options which is really useful in real 
applications:

1) Dumping only some table types. There is usually no need to dump HEAP tables 
as they anyway can be recreated with server restart, MERGE tables as this will 
produce major mess during recovery as rows will be attempted to insert both to 
MERGE table and original underlaying table.  Sometimes it does not make sence 
to dump MYISAM tables - in case they are backed up by faster BACKUP TABLE.

2) Currently mysqldump requires you to dump fixed list of tables/databases or 
all of them. This is not that comportable. Often you would need to dump all 
but several tables/databases or dump some tables from different databases in 
one run. 


How this would be solved:

1) Controling table types
 - Options --dump-table-types=TYPE1,TYPE2,TYPE3 and    --skip-table-
types=TYPE1,TYPE2,TYPE3 will be added.  This would allow to specify for which 
types you do not want data to be dumped
 - Option --persistent-tables  as the alias to --skip-table-types=HEAP,MERGE
   To easier programm usage
 - Option --opt will imply --persistent-tables as this is how you would  
usually like to dump your data.

2) Controling table list
  --only-dump-tables=d1.t1,d2.t2,t3  Dump only these tables. One may allow 
specify database name to match. If table name is specified without database 
name it will be dumped from all specified databases. Of course this option 
makes sense only for multiple databases.
  --skip-dump-tables=d1.t1,d2.t2,t3  Skip these tables from dump. Works 
exactly the same way.
  --skip-databases=d1,d2,d3   Do not dump some of the databases. Main purpose 
is to skip cache databases etc.  Should be together with --all-databases
  --dump-regexp=regexp
  --skip-regexp=regexp These options are to make mysqldump really powerfull 
backup tool by allowing to match tables to be dumped against these regexp. 
Full table name (with database name) is matched to be uniform.