code review for attach on demand (AOD) fix for Windows (7028668)

[Daniel D. Daugherty]

Greetings,

I have minor fixes to the Attach On Demand (AOD) Windows
specific code that I'd like to get into T&L snapshot for
OpenJDK7-B136 (next week):

   http://cr.openjdk.java.net/~dcubed/7028668-webrev/0/

I'm adding more info to the default detail message for an
OpenProcess() failure. I'm also getting a process handle
in a different way when a Java process tries to attach to
itself. If the new technique fails, then we fall back to
the original OpenProcess() code.

Thanks, in advance, for any comments.

Dan