Fix JS array types

[gaillarddamien]

Support for array types was requested in issue #317 and its implementation recently merged into develop (PR #340).
However, there were a few issues with it.
I will try and summarize what this PR addresses.

• int and float array types:
  it fails to decode int and float arrays (other than Int8Array and Uint8Array): an array of the right size is returned, but it is filled with the first value from the original array.

  #input:
  {"value": [-1,-2,47897,-3.4,-4,-5,-6,47879,1,9,-7,7877444],"type":"Int16Array","name":"test"}
  #output:
  {"value":[-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1],"type":"Int16Array","name":"test"}

  This is because the decoding function always returns the first byte (index 0) regardless of how it is invoked (i has no effect on these calls).

• boolean array type:

  #input:
  {"value": [false,false,true,true,false,true,false,false,true,true,false,true,true,true,false],"type":"booleanArray","name":"Hello"}

  It fails here with the following error byte length of Uint32Array should be a multiple of 4.
  And I believe the bytes would then be built with bits reversed.