corba autoconf macros

[Dan Kegel]

I've been using the corbaconf macros at http://corbaconf.kiev.ua/
They look potentially very useful, and I've already gotten some
benefit from them.

However...
It seems wrong that they update universal variables like LIBS.
This gets in the way of non-corba programs in the same package.
It also seems messy that the symbols they define don't have a
uniform prefix.  ORB_ is almost common, but many of their symbols
also use IDL_ or other prefixes.

Also, these macros can't be used in a system that uses multiple
CORBA implementations, as they would clash.

Finally, in order to be contributed to the official autoconf macro archive
http://www.gnu.org/software/ac-archive/
perhaps some overlaps should be reduced, e.g. contribute
YAD_CHECK_INCLUDE_LIB back to the archives as an update to AC_CHECK_LIB?

I propose a few ideas for a new version of the macros:

1) move uniformly to the prefix CORBA_ for all symbols
2) For a particular orb, move uniformly to the prefix CORBA_ORBNAME_ for all 
symbols
3) CHECK_ORB would invoke all the other macros and copy all the CORBA_ORBNAME_
   symbols to CORBA_ for the first orb it found
4) Allow subsetting, e.g. add a CORBA_DYNAMIC_LIBS for the libraries needed for 
dynamic any support
   This is important for embedded systems, as it reduces footprint.

I'm slowly doing a few of these on my own, would prefer to coordinate.
Thanks,
Dan