Lots of changes/new features

- To override the last used boot mode on soft reboot, you only need to press A if you want to boot to the default option. Holding L(+payload button)/R is enough for the other modes.
- Added version number to the config menu
- Replaced the memsearch algorithm with a faster one
- Integrated 3ds_injector from @yifanlu. This brings us region free and all the other FreeMultiPatcher patches. Other than that, you now have the possibility to display the currently booted NAND/FIRM in System Settings!
- Rewritten most code for the config menu. You now can navigate to the first/last options with left and right.
- You can now choose the 9.0 FIRM to be default in the config menu. This will essentially switch "no buttons" and L in both modes.
- You can now choose the second emuNAND to be default in the config menu. This will essentially switch "B is not pressed" and "B is pressed".
- When the second emuNAND is booted, it will persist like the other boot options on soft reboot
- Bugfixes

injector/source/ifile.c

@@ -0,0 +1,105 @@
+#include <3ds.h>
+#include "ifile.h"
+#include "fsldr.h"
+
+Result IFile_Open(IFile *file, FS_Archive archive, FS_Path path, u32 flags)
+{
+  Result res;
+
+  res = FSLDR_OpenFileDirectly(&file->handle, archive, path, flags, 0);
+  file->pos = 0;
+  file->size = 0;
+  return res;
+}
+
+Result IFile_Close(IFile *file)
+{
+  return FSFILE_Close(file->handle);
+}
+
+Result IFile_GetSize(IFile *file, u64 *size)
+{
+  Result res;
+
+  res = FSFILE_GetSize(file->handle, size);
+  file->size = *size;
+  return res;
+}
+
+Result IFile_Read(IFile *file, u64 *total, void *buffer, u32 len)
+{
+  u32 read;
+  u32 left;
+  char *buf;
+  u64 cur;
+  Result res;
+
+  if (len == 0)
+  {
+    *total = 0;
+    return 0;
+  }
+
+  buf = (char *)buffer;
+  cur = 0;
+  left = len;
+  while (1)
+  {
+    res = FSFILE_Read(file->handle, &read, file->pos, buf, left);
+    if (R_FAILED(res))
+    {
+      break;
+    }
+
+    cur += read;
+    file->pos += read;
+    if (read == left)
+    {
+      break;
+    }
+    buf += read;
+    left -= read;
+  }
+
+  *total = cur;
+  return res;
+}
+
+Result IFile_Write(IFile *file, u64 *total, void *buffer, u32 len, u32 flags)
+{
+  u32 written;
+  u32 left;
+  char *buf;
+  u64 cur;
+  Result res;
+
+  if (len == 0)
+  {
+    *total = 0;
+    return 0;
+  }
+
+  buf = (char *)buffer;
+  cur = 0;
+  left = len;
+  while (1)
+  {
+    res = FSFILE_Write(file->handle, &written, file->pos, buf, left, flags);
+    if (R_FAILED(res))
+    {
+      break;
+    }
+
+    cur += written;
+    file->pos += written;
+    if (written == left)
+    {
+      break;
+    }
+    buf += written;
+    left -= written;
+  }
+
+  *total = cur;
+  return res;
+}