Move new + and * operations into next.

  Implement special case for hash map integer operations.
Merge pull request #55 from patrickgombert/add-multiply-in-next

Move new + and * operations into next.
Introduce subtraction which is implemented in java
Merge pull request #56 from patrickgombert/negation

Introduce subtraction which is implemented in java
Introduce increment implemented in java
Introduce decrement implemented in java
Merge pull request #57 from patrickgombert/inc-dec

Introduce increment & decrement implemented in java
Change int preserving ops from a hash-specific name to more general name
Merge pull request #58 from patrickgombert/rename-int-preserved-ops

Change int preserving ops from a hash-specific name to more general name
Implement BitAnd in Java
Merge pull request #59 from patrickgombert/bitand

Implement BitAnd in Java
Add bit-or
Add bit-xor
Add bit shift left
Merge pull request #60 from patrickgombert/bits-and-whatnot

Bits and whatnot