replace limits.h with climits

The former was deprecated with C++14. The standard says they are the same
with one exception:

The header<climits>defines all macros the same as the C standard library
header<limits.h>.

[Note:The types of the constants defined by macros in<climits>are not
required to match the types to which themacros refer.— end note]

Signed-off-by: Rosen Penev <rosenp@gmail.com>

src/Main.cxx

@@ -115,7 +115,7 @@
 #include <locale.h>
 #endif
 
-#include <limits.h>
+#include <climits>
 
 static constexpr size_t KILOBYTE = 1024;
 static constexpr size_t MEGABYTE = 1024 * KILOBYTE;

src/db/update/InotifySource.cxx

@@ -25,10 +25,10 @@
 #include "Log.hxx"
 
 #include <cerrno>
+#include <climits>
 
 #include <sys/inotify.h>
 #include <stdint.h>
-#include <limits.h>
 
 bool
 InotifySource::OnSocketReady(gcc_unused unsigned flags) noexcept

src/fs/Limits.hxx

@@ -20,8 +20,9 @@
 #ifndef MPD_FS_LIMITS_HXX
 #define MPD_FS_LIMITS_HXX
 
+#include <climits>
+
 #include <stddef.h>
-#include <limits.h>
 
 #if defined(_WIN32)
 static constexpr size_t MPD_PATH_MAX = 260;

src/zeroconf/ZeroconfGlue.cxx

@@ -27,9 +27,10 @@
 #include "Log.hxx"
 #include "util/Compiler.h"
 
+#include <climits>
+
 #include <string.h>
 #include <unistd.h>
-#include <limits.h>
 
 #ifndef HOST_NAME_MAX
 /* HOST_NAME_MAX is not a portable macro; it is undefined on some