Allow some of the old tests to run.
Add license and minor cleanup
Update to rust HEAD
Initial version of serialization.
Change the json enum serialization to {"variant":["fields", ...]}

test bench_enum::bench_decoder_dog                   ... bench:       112 ns/iter (+/- 15)
test bench_enum::bench_decoder_frog                  ... bench:       336 ns/iter (+/- 6)
test bench_enum::bench_deserializer_dog              ... bench:       120 ns/iter (+/- 4)
test bench_enum::bench_deserializer_frog             ... bench:       317 ns/iter (+/- 15)
test bench_map::bench_decoder_000                    ... bench:       528 ns/iter (+/- 13)
test bench_map::bench_decoder_003                    ... bench:      2459 ns/iter (+/- 74)
test bench_map::bench_decoder_100                    ... bench:     70756 ns/iter (+/- 1979)
test bench_map::bench_deserializer_000               ... bench:       753 ns/iter (+/- 30)
test bench_map::bench_deserializer_003               ... bench:      2574 ns/iter (+/- 111)
test bench_map::bench_deserializer_100               ... bench:     62374 ns/iter (+/- 1714)
test bench_struct::bench_decoder_0_0                 ... bench:       609 ns/iter (+/- 14)
test bench_struct::bench_decoder_1_0                 ... bench:      1620 ns/iter (+/- 44)
test bench_struct::bench_decoder_1_5                 ... bench:      4393 ns/iter (+/- 88)
test bench_struct::bench_deserializer_0_0            ... bench:       699 ns/iter (+/- 10)
test bench_struct::bench_deserializer_1_0            ... bench:      2160 ns/iter (+/- 53)
test bench_struct::bench_deserializer_1_5            ... bench:      4987 ns/iter (+/- 87)
test bench_vec::bench_decoder_int_000                ... bench:        20 ns/iter (+/- 1)
test bench_vec::bench_decoder_int_003                ... bench:       148 ns/iter (+/- 3)
test bench_vec::bench_decoder_int_100                ... bench:      1009 ns/iter (+/- 44)
test bench_vec::bench_decoder_u8_000                 ... bench:        16 ns/iter (+/- 0)
test bench_vec::bench_decoder_u8_003                 ... bench:       152 ns/iter (+/- 12)
test bench_vec::bench_decoder_u8_100                 ... bench:      1457 ns/iter (+/- 95)
test bench_vec::bench_deserializer_int_000           ... bench:        16 ns/iter (+/- 0)
test bench_vec::bench_deserializer_int_003           ... bench:       153 ns/iter (+/- 9)
test bench_vec::bench_deserializer_int_100           ... bench:      1015 ns/iter (+/- 38)
test bench_vec::bench_deserializer_u8_000            ... bench:        16 ns/iter (+/- 1)
test bench_vec::bench_deserializer_u8_003            ... bench:       160 ns/iter (+/- 130)
test bench_vec::bench_deserializer_u8_100            ... bench:      1225 ns/iter (+/- 112)
test json::tests::bench_decoder_large                ... bench:   1979093 ns/iter (+/- 67769)
test json::tests::bench_decoder_small                ... bench:      4644 ns/iter (+/- 208)
test json::tests::bench_decoder_streaming_large      ... bench:    848383 ns/iter (+/- 96301)
test json::tests::bench_decoder_streaming_small      ... bench:      1834 ns/iter (+/- 120)
test json::tests::bench_deserializer_large           ... bench:   1882598 ns/iter (+/- 137262)
test json::tests::bench_deserializer_small           ... bench:      3945 ns/iter (+/- 161)
test json::tests::bench_deserializer_streaming_large ... bench:    990086 ns/iter (+/- 157794)
test json::tests::bench_deserializer_streaming_small ... bench:      2135 ns/iter (+/- 211)