feat(parse): Allow mutable parsing

[epage]

This is a step towards #72

v0.4.7

json/basic/canada       time:   [10.272 ms 10.308 ms 10.347 ms]
json/verbose/canada     time:   [32.539 ms 32.714 ms 32.893 ms]
json/dispatch/canada    time:   [8.9747 ms 8.9926 ms 9.0118 ms]
json/streaming/canada   time:   [10.612 ms 10.667 ms 10.726 ms]

#274

json/basic/canada       time:   [10.231 ms 10.253 ms 10.279 ms]
json/unit/canada        time:   [9.3250 ms 9.3526 ms 9.3808 ms]
json/verbose/canada     time:   [29.832 ms 29.891 ms 29.957 ms]
json/dispatch/canada    time:   [8.4980 ms 8.5093 ms 8.5211 ms]
json/streaming/canada   time:   [10.007 ms 10.044 ms 10.081 ms]

#275

json/basic/canada       time:   [10.505 ms 10.526 ms 10.548 ms]
json/unit/canada        time:   [9.5206 ms 9.5450 ms 9.5702 ms]
json/verbose/canada     time:   [30.530 ms 30.585 ms 30.642 ms]
json/dispatch/canada    time:   [8.7744 ms 8.7937 ms 8.8141 ms]
json/streaming/canada   time:   [9.6165 ms 9.6393 ms 9.6637 ms]

[coveralls]

Pull Request Test Coverage Report for Build 5476429851

• 142 of 204 (69.61%) changed or added relevant lines in 13 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.1%) to 50.627%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/combinator/branch.rs	1	2	50.0%
src/error.rs	0	1	0.0%
src/trace/mod.rs	0	1	0.0%
src/binary/mod.rs	32	34	94.12%
src/combinator/core.rs	8	12	66.67%
src/combinator/multi.rs	18	23	78.26%
src/combinator/parser.rs	27	40	67.5%
src/ascii/mod.rs	35	51	68.63%
src/parser.rs	3	22	13.64%

Totals
Change from base Build 5476419497:	-0.1%
Covered Lines:	1251
Relevant Lines:	2471

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💛 - Coveralls