Implement the ability to use bit variables (HAST-235)

[Piedone]

For #2 we need to store bit values in an efficient way. We could use bools, which on the FPGA will be represented as bits (which is great), but probably a more explicit approach would be better. Options:

• BitArray: https://msdn.microsoft.com/en-us/library/system.collections.bitarray(v=vs.110).aspx
• BitVector32: https://msdn.microsoft.com/en-us/library/system.collections.specialized.bitvector32.aspx

See: http://stackoverflow.com/questions/352089/why-cant-i-define-a-bit-in-c-sharp

Jira issue

[Piedone]

These could be handled by "compiler intrinsics" of the Transformer specifically: instead of actually transforming them an efficient pre-created hardware implementation could be used (similarly how ImmutableArray support works).

Maybe having an instrinsic behaviour for BitMask would actually be the best: have a configurable-sized (as many bits as you wish) signed/unsigned register with support for basic operators like arithmetic, shifting... Would also help #21.