[CMake] CMake CVS gratuitous /bin directory

[Brad King]

Brandon J. Van Every wrote:
>> 1.) The error message is worded poorly.
>> 2.) The error is actually referring to the .dll, not the .lib and
>>     is due to a bug with trailing slashes in the install destination.
>> 3.) The .lib is mentioned even though it is not actually installed.
>>
>> I've fixed #1 and #2 in CVS which should be enough to install Chicken 
>> properly.  Problem #3 will be fixed as part of more general changes 
>> I'm making.
>>
> Now CMake CVS is generating additional libraries of the form 
> "liblibname.dll.a".  It seems whatever you are doing for *.dll.a, 
> doesn't have the liblib fix applied to it.  I am setting PREFIX to "".

When I got to that point in the code I wasn't sure of the proper design. 
  The problem is that for SUFFIX it does not make sense to use the same 
attribute for both the .dll and the .dll.a parts because the two files 
cannot have the same extension.  For PREFIX it is okay to have the same 
value for both files but on Cygwin for example the convention is "cyg" 
for the .dll and "lib" for the .dll.a.

In order to be consistent for both PREFIX and SUFFIX and allow them to 
be set separately for the DLL and the import library, I created new 
properties IMPORT_PREFIX and IMPORT_SUFFIX.  I haven't updated the 
documentation because these are part of incremental commits for a larger 
set of changes.  You can set the target property IMPORT_PREFIX to "" 
also to solve the problem.

-Brad