Work around x11-links lossage with native X on NetBSD 5.

x11-links rejects xf86vidmodeproto because it's too old according
to the pkgsrc X xf86vidmodeproto bl3 file (which is at best dubious
logic) and doesn't link it. Then the .pc file isn't available, so
this package's configure script silently fails running pkg-config
and sets XVIDTUNE_LIBS to empty. The build then fails at link time
because no X libs at all have been requested. Fix it by feeding in
the result of running the same pkg-config invocation outside
pkgsrc. The fact that the native xf86vidmode is "too old" does not
itself break the package.
Changes 5.5.25:
* The --safe-mode server option now is deprecated and will be removed in MySQL
  5.6.
* Performance: InnoDB: Improved the algorithm related to adaptive flushing.
  This fix increases the rate of flushing in cases where compression is used
  and the data set is larger than the buffer pool, leading to eviction.
* InnoDB: In a transaction using the REPEATABLE READ isolation level, an UPDATE
  or DELETE statement for an InnoDB table could sometimes overlook rows
  recently committed by other transactions. As explained in Section 14.3.9.2,
  “Consistent Nonlocking Reads”, DML statements within a REPEATABLE READ
  transaction apply to rows committed by other transactions, even if a query
  could not see those rows.
* InnoDB: The Innodb_buffer_pool_pages_flushed status variable was incorrectly
  set to twice the value it should be. Its value should never exceed the value
  of Innodb_pages_written.
* InnoDB: The error handling and message was improved for attempting to create
  a foreign key with a column referencing itself. The message suggested
  a potential problem with the data dictionary, when no such problem existed.
* InnoDB: The CHECK TABLE statement could fail for a large InnoDB table due to
  a timeout value of 2 hours. For typical storage devices, the issue could
  occur for tables that exceeded approximately 200 or 350 GB, depending on I/O
  speed. The fix relaxes the locking performed on the table being checked,
  which makes the timeout less likely. It also makes InnoDB recognize the
  syntax CHECK TABLE QUICK, which avoids the possibility of the timeout
  entirely.
* Replication: It was theoretically possible for concurrent execution of more
  than one instance of SHOW BINLOG EVENTS to crash the MySQL Server.
* Replication: Statements using AUTO_INCREMENT, LAST_INSERT_ID(), RAND(), or
  user variables could be applied in the wrong context on the slave when using
  statement-based replication and replication filtering server options (see
  Section 16.2.3, “How Servers Evaluate Replication Filtering Rules”).
* Replication: An INSERT into a table that has a composite primary key that
  includes an AUTO_INCREMENT column that is not the first column of this
  composite key is not safe for statement-based binary logging or replication.
  Such statements are now marked as unsafe and fail with an error when using
  the STATEMENT binary logging format. For more information, see Section
  16.1.2.3, “Determination of Safe and Unsafe Statements in Binary Logging”, as
  well as Section 16.4.1.1, “Replication and AUTO_INCREMENT”.
Updated databases/mysql55 to 5.5.25