multidict 3.0.0

Changes

• Refactor internal data structures: main dict operations are about
  100% faster now.

• Preserve order on multidict updates #68

  Updates are md[key] = val and md.update(...) calls.

  Now the last entry is replaced with new key/value pair, all
  previous occurrences are removed.

  If key is not present in dictionary the pair is added to the end

• Force keys to str instances #88

• Implement .popall(key[, default]) #84

• .pop() removes only first occurence, .popone() added #92

• Implement dict's version #86

• Proxies are not pickable anymore #77