added delete/3 - resolves #46
added subset/2 - resolves #49

moved member check logic from MemberCheck to ListUtils so it can be
reused by Subset
added random/1 arithmetic function - resolves #20
added AbstractTwoIntegerArgumentsCalculatable - for use by #47, #51 and #52
added bitwise "and" operation - resolves #52
added bit shift right operation - resolves #51