[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/filesup.h

@@ -0,0 +1,57 @@
+/*
+ * PROJECT:     ReactOS Setup Library
+ * LICENSE:     GPL-2.0+ (https://spdx.org/licenses/GPL-2.0+)
+ * PURPOSE:     File support functions.
+ * COPYRIGHT:   Copyright 2017-2018 Hermes Belusca-Maito
+ */
+
+#pragma once
+
+#if 0
+
+BOOLEAN
+IsValidPath(
+    IN PCWSTR InstallDir);
+
+#endif
+
+NTSTATUS
+ConcatPaths(
+    IN OUT PWSTR PathElem1,
+    IN SIZE_T cchPathSize,
+    IN PCWSTR PathElem2 OPTIONAL);
+
+BOOLEAN
+DoesPathExist(
+    IN HANDLE RootDirectory OPTIONAL,
+    IN PCWSTR PathName);
+
+BOOLEAN
+DoesFileExist(
+    IN HANDLE RootDirectory OPTIONAL,
+    IN PCWSTR PathName OPTIONAL,
+    IN PCWSTR FileName);
+
+BOOLEAN
+NtPathToDiskPartComponents(
+    IN PCWSTR NtPath,
+    OUT PULONG pDiskNumber,
+    OUT PULONG pPartNumber,
+    OUT PCWSTR* PathComponent OPTIONAL);
+
+NTSTATUS
+OpenAndMapFile(
+    IN HANDLE RootDirectory OPTIONAL,
+    IN PCWSTR PathName OPTIONAL,
+    IN PCWSTR FileName,             // OPTIONAL
+    OUT PHANDLE FileHandle,         // IN OUT PHANDLE OPTIONAL
+    OUT PHANDLE SectionHandle,
+    OUT PVOID* BaseAddress,
+    OUT PULONG FileSize OPTIONAL);
+
+BOOLEAN
+UnMapFile(
+    IN HANDLE SectionHandle,
+    IN PVOID BaseAddress);
+
+/* EOF */