RELEASE: v3.0.2

[Warren Young]

More minor post-3.0.0 fixes.  This breaks the ABI yet again, which  
should be the last time until 4.0.  But I said that for 3.0.1, too. :)

   o Increased float to string conversion precision from 7 to 9 and
     double from 16 to 17 digits.  Previous values weren't enough
     near the maximum values that each can hold.

   o Replaced Query's safe bool mechanism with an override of
     basic_ios::operator void*() to avoid a conflict between the
     two mechanisms.  As the base class version isn't virtual,
     this is arguably evil, but it should be harmless in typical use.
     Besides, testing Query in bool context usually isn't the right
     thing anyway: test the result set instead.

   o Made ConnectionPool::grab() virtual.

   o Overriding ConnectionPool::grab() and release() in
     examples/cpool.cpp to show how to do connection-in-use count
     limiting.  Also, added a few more output indicator states to
     allow one to better understand program flow.

As always, it's available at http://tangentsoft.net/mysql++/

P.S. I will be out of town most of this week, so I'm not likely to be  
able to respond to list posts often, if at all.  If 3.0.2 is horribly  
broken, 3.0.1 is still available on the server in the raw view of the  
release directory, as are all past releases.