Bug #10229 IM's show instance status never displays version

Description:
"show instance status" always shows version as "unknown"

mysql> show instance status mysqld3;
        +---------------+--------+---------+
        | instance_name | status | version |
        +---------------+--------+---------+
        | mysqld3       | online | unknown |
        +---------------+--------+---------+
        1 row in set (0.00 sec)
        

How to repeat:
issue "show instance status" command and check that the version string is not shown

Suggested fix:
This thing was broken when it was decided to drop persistent connection to the instance. Now is is a bit tricky to implement. Probably we should drop this field. But more likely we should parse the output of appropriate "mysqld" binary

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/25427

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/internals/25480

With the fix IM parses output of mysqld --no-defaults --version for each instance binary to get the version line. The result looks like this:

mysql> show instance status mysqld;
+---------------+---------+-------------------------------------------------------------------+
| instance_name | status  | version                                                           |
+---------------+---------+-------------------------------------------------------------------+
| mysqld        | offline |   Ver 5.0.5-beta-debug for pc-linux on i686 (Source distribution) |
+---------------+---------+-------------------------------------------------------------------+
1 row in set (0.00 sec)

Documented in 5.0.7 changelog.