* add function for one-off calculation

* sha3: simplifies Read function

* sha3: remove if from Read

* complate reset of the SHA-3 code. Affects mostly the code in sha3.go
* fixes a bug  which causes SHAKE implementation to crash
* implementation of Read()/Write() avoid unnecessary buffering as much
  as possible
* NOTE: at some point I've done separated implementation for SumXXX,
  functions, but after optimizing implementation of Read/Write/Sum, the
  gain wasn't that big

Current speed on Initial speed on i7-8665U@1.90

BenchmarkPermutationFunction 	 			 1592787	       736 ns/op	 271.90 MB/s	       0 B/op	       0 allocs/op
BenchmarkSha3Chunk_x01/SHA-3/224         	   98752	     11630 ns/op	 176.02 MB/s	       0 B/op	       0 allocs/op
BenchmarkSha3Chunk_x01/SHA-3/256         	   92508	     12447 ns/op	 164.46 MB/s	       0 B/op	       0 allocs/op
BenchmarkSha3Chunk_x01/SHA-3/384         	   76765	     15206 ns/op	 134.62 MB/s	       0 B/op	       0 allocs/op
BenchmarkSha3Chunk_x01/SHA-3/512         	   54333	     21932 ns/op	  93.33 MB/s	       0 B/op	       0 allocs/op
BenchmarkSha3Chunk_x16/SHA-3/224         	   10000	    102161 ns/op	 160.37 MB/s	       0 B/op	       0 allocs/op
BenchmarkSha3Chunk_x16/SHA-3/256         	   10000	    106531 ns/op	 153.80 MB/s	       0 B/op	       0 allocs/op
BenchmarkSha3Chunk_x16/SHA-3/384         	    8641	    137272 ns/op	 119.35 MB/s	       0 B/op	       0 allocs/op
BenchmarkSha3Chunk_x16/SHA-3/512         	    6340	    189124 ns/op	  86.63 MB/s	       0 B/op	       0 allocs/op
BenchmarkShake_x01/SHAKE-128             	  167062	      7149 ns/op	 188.83 MB/s	       0 B/op	       0 allocs/op
BenchmarkShake_x01/SHAKE-256             	  151982	      7748 ns/op	 174.24 MB/s	       0 B/op	       0 allocs/op
BenchmarkShake_x16/SHAKE-128             	   12963	     87770 ns/op	 186.67 MB/s	       0 B/op	       0 allocs/op
BenchmarkShake_x16/SHAKE-256             	   10000	    105554 ns/op	 155.22 MB/s	       0 B/op	       0 allocs/op
BenchmarkCShake/cSHAKE-128               	  109148	     10940 ns/op	 187.11 MB/s	       0 B/op	       0 allocs/op
BenchmarkCShake/cSHAKE-256               	   90324	     13211 ns/op	 154.94 MB/s	       0 B/op	       0 allocs/op
PASS

Initial speed on i7-8665U

> go test -bench=. -test.cpu=1
goos: linux
goarch: amd64
pkg: github.com/henrydcase/nobs/hash/sha3
BenchmarkPermutationFunction 	 1634836	       732 ns/op	 273.18 MB/s
BenchmarkSha3_512_MTU        	   78438	     15340 ns/op	  88.00 MB/s
BenchmarkSha3_384_MTU        	  108807	     11025 ns/op	 122.45 MB/s
BenchmarkSha3_256_MTU        	  136902	      8767 ns/op	 153.98 MB/s
BenchmarkSha3_224_MTU        	  143377	      8355 ns/op	 161.57 MB/s
BenchmarkShake128_MTU        	  163569	      7108 ns/op	 189.94 MB/s
BenchmarkShake256_MTU        	  156534	      7643 ns/op	 176.64 MB/s
BenchmarkShake256_16x        	   10000	    112109 ns/op	 146.14 MB/s
BenchmarkShake256_1MiB       	     204	   5877014 ns/op	 178.42 MB/s
BenchmarkSha3_512_1MiB       	     100	  10967026 ns/op	  95.61 MB/s
PASS
ok  	github.com/henrydcase/nobs/hash/sha3	13.855s

* Reset Makefile after adding go.mod
* Remove ``build`` directory
* Simiplifies makefile
* shake: Make xorIn copyOut platform specific

* xorIn and copyOut function pointers cause input and output data
  to be moved to heap. This degrades performance of calling code.

* This change removes usage of those function pointers. We will always
  use unaligned implementation as it's faster (but may crash on some
  systems)

* Benchmark compares generic vs unaligned xorIn and copyOut

benchmark                          old ns/op     new ns/op     delta
BenchmarkPermutationFunction-4     463           815           +76.03%
BenchmarkShake128_MTU-4            4443          8180          +84.11%
BenchmarkShake256_MTU-4            4739          9060          +91.18%
BenchmarkShake256_16x-4            71886         132629        +84.50%
BenchmarkShake256_1MiB-4           3695138       6649012       +79.94%
BenchmarkCShake128_448_16x-4       21210         24611         +16.03%
BenchmarkCShake128_1MiB-4          3009342       3396496       +12.87%
BenchmarkCShake256_448_16x-4       26034         27785         +6.73%
BenchmarkCShake256_1MiB-4          3654713       3829404       +4.78%