[SETUPLIB][USETUP] Move some code to the SetupLib.

- filesup.c's functions ConcatPaths(), Does[Path|File]Exist(), NtPathToDiskPartComponents(), OpenAndMapFile(), UnMapFile();
- Move the inicache library to setuplib as it'll be used for the 1st stage GUI setup too (indeed, there is no good INI file API
  under Win32; the Win32 profile "API" is just good enough to manipulate the win16 ini files, and are here anyways for backward
  compatibility purposes only);
- Move the OS detector too.
- Remove the duplicated ConcatPaths() code in arcname.c.

svn path=/branches/setup_improvements/; revision=74634
svn path=/branches/setup_improvements/; revision=74638

base/setup/lib/CMakeLists.txt

@@ -1,9 +1,12 @@
 
 list(APPEND SOURCE
     arcname.c
+    filesup.c
     fsutil.c
     genlist.c
+    inicache.c
     ntverrsrc.c
+    osdetect.c
     partlist.c
     precomp.h)