Use integer types more consistently in membuffer cache.
Use integer types more consistently in membuffer cache.

* subversion/libsvn_subr/cache-membuffer.c
  (entry_group_t): same type for entry count as for entry indexes
  (get_index): explicitly cast from size_t to entry index
  (svn_cache__membuffer_cache_create): fix 32/64 bit conversion warnings

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1405535 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion