1. Update semantics of how plugins determine
   the size and space of the dollop that they
	 will plop. 
2. Add sorting for plugin invocation based on
   lexigraphical sorting.

1. Allow AddressDollop() to tell Zipr whether
the dollops should be coalesced. Defaults to true.

2. Allow the plugin to retarget a pin.

Give the source address for the instruction
that is targeting the dollop to be placed. This
will give another signal to placement plugins
to help them make a decision.

Let a plugin tell us about where to plop a dollop.
This change includes a

1. utils namespace with a function to calculate
the worst case instruction size.
2. Dollop_t type that can be used to describe
and pass around a dollop.

1. Add support for plugins to call certain
Zipr_t functions. This meant making a class
that is Zipr_t and then converting the actual
implementation to a subclass (ZiprImpl_t). The
Zipr_t goes in the zipr_sdk.

2. Ask all plugins about each instruction
and determine whether there are any takers
for plopping.

3. When plopping an instruction, consider
whether or not a plugin asked to do the plopping.
If so, let it do the work.