Merge branch 'master' into b

$ benchcmp gollrb.bench b-gen.bench
benchmark                                   old ns/op       new ns/op	delta
BenchmarkNamePredicate                      1369329         1444990	+5.53%
BenchmarkLargeSetsNoIntersection            72329029        64975716	-10.17%
BenchmarkVeryLargeSetsSmallIntersection     890824761       408784476	-54.11%
BenchmarkHelplessContainsChecker            35314797618     30673240485	-13.14%
BenchmarkNetAndSpeed                        19694146        19486797	-1.05%
BenchmarkKeanuAndNet                        15340756        15317415	-0.15%
BenchmarkKeanuAndSpeed                      17902709        18042030	+0.78%
BenchmarkKeanuOther                         53452058        50984817	-4.62%
BenchmarkKeanuBullockOther                  90827780        86536510	-4.72%

benchmark                                   old allocs     new allocs	delta
BenchmarkNamePredicate                      1339           1339	+0.00%
BenchmarkLargeSetsNoIntersection            22603          22674	+0.31%
BenchmarkVeryLargeSetsSmallIntersection     65787          65860	+0.11%
BenchmarkHelplessContainsChecker            1713541        1713669	+0.01%
BenchmarkNetAndSpeed                        17135          17146	+0.06%
BenchmarkKeanuAndNet                        15802          15802	+0.00%
BenchmarkKeanuAndSpeed                      16397          16396	-0.01%
BenchmarkKeanuOther                         30148          30149	+0.00%
BenchmarkKeanuBullockOther                  35542          35544	+0.01%

benchmark                                   old bytes     new bytes	delta
BenchmarkNamePredicate                      96226         95842	-0.40%
BenchmarkLargeSetsNoIntersection            1165914       119725	+2.69%
BenchmarkVeryLargeSetsSmallIntersection     2760072       2777798	+0.64%
BenchmarkHelplessContainsChecker            84388448      84351168	-0.04%
BenchmarkNetAndSpeed                        1414837       1425752	+0.77%
BenchmarkKeanuAndNet                        1247249       1247453	+0.02%
BenchmarkKeanuAndSpeed                      1275522       1275243	-0.02%
BenchmarkKeanuOther                         2021107       2021497	+0.02%
BenchmarkKeanuBullockOther                  2682243       2683250	+0.04%