[#7] support little/big endian operations on a byte array

[rlespinasse]

• Create BigEndianOperations accessor with

  • Mask function,
  • InclusiveMerge function,
  • ExclusiveMerge function,
  • ExtractBytes function.

• Create LittleEndianOperations accessor with

  • Mask function,
  • InclusiveMerge function,
  • ExclusiveMerge function,
  • ExtractBytes function.

• [LeftShift and RightShift functions are inversed #31] Fix LeftShift and RightShift functions.

• Add some Endianess-free operations

  • Add Mask function on two arrays of the same size,
  • Add InclusiveMerge function on two arrays of the same size,
  • Add ExclusiveMerge function on two arrays of the same size,
  • Add LeftPad function,
  • Add RightPad function.

Closes #7, #31

[coveralls]

Coverage remained the same at 100.0% when pulling c25839e on support-endianess into 92c23b7 on master.

[coveralls]

Coverage remained the same at 100.0% when pulling 0686393 on support-endianess into 92c23b7 on master.

[coveralls]

Coverage remained the same at 100.0% when pulling 5e68db1 on support-endianess into 92c23b7 on master.