[WIP] Tweak Pako to reduce object creation

This commit tweaks pako slightly to reduce the number of objects
it creates unecessarily.

docs/notes

@@ -3,3 +3,4 @@ Rebuilding inflator.js
 - Download pako from npm
 - Install browserify using npm
 - browserify utils/inflator.partial.js -o include/inflator.js -s inflator
+- apply changes from utils/inflator.diff.js to include/inflator.js

include/inflator.js

@@ -889,7 +889,7 @@ function inflate(strm, flush) {
   var len;                    /* length to copy for repeats, bits to drop */
   var ret;                    /* return code */
   var hbuf = new utils.Buf8(4);    /* buffer for gzip header crc calculation */
-  var opts;
+  var opts = {};
 
   var n; // temporary var for NEED_BITS
 
@@ -1425,7 +1425,7 @@ function inflate(strm, flush) {
       state.lencode = state.lendyn;
       state.lenbits = 7;
 
-      opts = {bits: state.lenbits};
+      opts.bits = state.lenbits;
       ret = inflate_table(CODES, state.lens, 0, 19, state.lencode, 0, state.work, opts);
       state.lenbits = opts.bits;
 
@@ -1556,7 +1556,7 @@ function inflate(strm, flush) {
          concerning the ENOUGH constants, which depend on those values */
       state.lenbits = 9;
 
-      opts = {bits: state.lenbits};
+      opts.bits = state.lenbits;
       ret = inflate_table(LENS, state.lens, 0, state.nlen, state.lencode, 0, state.work, opts);
       // We have separate tables & no pointers. 2 commented lines below not needed.
       // state.next_index = opts.table_index;
@@ -1573,7 +1573,7 @@ function inflate(strm, flush) {
       //state.distcode.copy(state.codes);
       // Switch to use dynamic table
       state.distcode = state.distdyn;
-      opts = {bits: state.distbits};
+      opts.bits = state.distbits;
       ret = inflate_table(DISTS, state.lens, state.nlen, state.ndist, state.distcode, 0, state.work, opts);
       // We have separate tables & no pointers. 2 commented lines below not needed.
       // state.next_index = opts.table_index;