patch for kdelibs/libltdl and cygwin os

Hi, 

the recent kdelibs/libltdl release contain some bugs, which make is unusable 
for cygwin. The following patches fixes this. 

--- ChangeLog ----- 
ltdl.m4 - fixed wrongly created config.h.in macros 
ltdl.c    - fixed buggy cygwin os detection 
----------------------

BTW: I have a cvs write access. Are I'm granted to check this in or do this 
someone else ? 

Thanks

Ralf