Start a lazy version of the Tree representation of graphs
Add Graph and DynGraph instances for lazy
Add a working version of lazy graph topologies
Add inPlaceFM function

inPlaceFM descends a map and updates elements as it goes down based on keys.
This might be useful when you want to alter a lot of elements but don't want
to be forced to recurse the tree more than once.
Add applyMutationsInPlace and applyMutationsInPlaceIns functions

Uses FiniteMaps' inPlaceFM function to apply mutations in batch mode.
Merge branch 'mutations' into fromfile
Specialize the return type of fromFile to gr Int Int

Need to find away around this
Add a Readable instance for the lazy graph