**    p     Show only next file change.
**    o     Show only previous file change.
**    u     Reload page in Unified Diff mode.
**    U     Reload page in Side-By-Side Diff mode.
**    0     Reload page in Hidden Diff mode.
**    d     Reload page and set current Diff mode as default.
**
** The keyboard shortcuts also apply to /ckout, /vinfo, /ci and /fdiff
** pages, and to /info pages describing check-in information.
*/
void vdiff_page(void){
  int ridFrom, ridTo;
  int diffType = 0;        /* 0: none, 1: unified, 2: side-by-side */
  Manifest *pFrom, *pTo;
  ManifestFile *pFileFrom, *pFileTo;
  const char *zBranch;