mysqld-debug.exe in 5.5.3 on windows

Fix:

- Do not rename PDB, install mysqld.pdb matching 
mysqld-debug.exe into bin\debug subdirectory

- Stack tracing code will now additionally look in 
debug subdirectory of the application directory 
for debug symbols.

- Small cleanup in stacktracing code: link with 
dbghelp rather than load functions dynamically 
at runtime, since dbghelp.dll is always present.

- Install debug binaries with WiX

cmake/install_macros.cmake:
  Add optional COMPONENT and PDB_DESTINATION 
  to INSTALL_DEBUG_TARGET
mysys/stacktrace.c:
  If binary is build with DBUG, also look in debug subdirectory
  of  executable directory. Packaging will put some PDBs there
  (e.g bin\mysqld-debug.exe will have corresponding pdb in 
  bin\debug)
  
  Also some cleanup: do not load dbghelp dynamically, instead
  link with it. dbghelp is present on all Windows starting with 
  XP.
packaging/WiX/CPackWixConfig.cmake:
  Install debug binaries
sql/CMakeLists.txt:
  Do not rename PDB for mysqld-debug.exe, install it in debug subdirectory