Bug 907

Instantiating ACE_Hash_Map_Manager incurs a lot of overhead in terms of code 
size to support infrequently used operations such as reverse iterators.  TAO 
has many instances of string->pointer maps that result in a new instantion of 
all of the classes, even though they are essentially the same except for 
pointer types.  Footprint could be saved by creating an adapter template to 
perform the appropriate casting to the desired pointer types, but only using 
one template instantiation of the string->pointer map.

Also, look into setting the default size of the initial hash map to reduce 
runtime footprint.

Note from previous investigation for doing this: A few months ago Irfan and I 
started looking into doing this, but ran into some complications making an 
adapter for ACE_Hash_Map_Entry due to its use of public member variables.  Then 
the effort got put off.

After the RTCORBA effort is done, I'll take responsibility for this one, but 
don't let this stop anyone else from taking it if they have time sooner.