Add getComm method to Distributors

Additionally, there is a minor documentation correction for the 
`Distributor` interface

src/Distributor.jl

@@ -14,8 +14,7 @@ in for the subtype:
 
     createFromSends(dist::DistributorImpl,exportPIDs::AbstractArray{PID})::Integer where PID <:Integer
 Sets up the Distributor object using a list of process IDs to which we
-export and the number of IDs being exported.  Returns the number of
-IDs this processor will be receiving.
+export.  Returns the number of IDs this processor will be receiving.
 
     createFromRecvs(dist::DistributorImpl, remoteGIDs::AbstractArray{GID}, remotePIDs::AbstractArray{PID})::Tuple{AbstractArray{GID}, AbstractArray{PID}} where GID <: Integer where PID <: Integer
 Sets up the Distributor object using a list of remote global IDs and corresponding
@@ -72,7 +71,7 @@ objects set to this processor
 """
 function resolve(dist::Distributor, exportObjs::AbstractArray{T})::AbstractArray{T} where T
     resolvePosts(dist, exportObjs)
-    resolveWaits(dist)
+    resolveWaits(dist)::AbstractArray{T}
 end
 
 """

src/MPIDistributor.jl

@@ -341,6 +341,11 @@ function createReverseDistributor(dist::MPIDistributor{GID, PID, LID}
 end
 
 
+
+#### General Interface ####
+
+getComm(dist::MPIDistributor) = dist.comm
+
 #### Distributor interface ####
 
 function createFromSends(dist::MPIDistributor{GID, PID, LID}, exportPIDs::AbstractArray{PID, 1})::Integer where GID <:Integer where PID <:Integer where LID <:Integer

src/RowMatrix.jl

@@ -65,8 +65,6 @@ Additionally, Julia's `mul!` and `*` functions are implemented for `RowMatrix`-`
 abstract type RowMatrix{Data <: Number, GID <: Integer, PID <: Integer, LID <: Integer} <: AbstractArray{Data, 2}
 end
 
-#REVIEW look into requiring A_mul_B! instead and having apply! call that
-
 isFillActive(matrix::RowMatrix) = !isFillComplete(matrix)
 isLocallyIndexed(matrix::RowMatrix) = !isGloballyIndexed(matrix)
 

src/SerialComm.jl

@@ -130,3 +130,5 @@ end
 function createDistributor(comm::SerialComm{GID, PID, LID})::SerialDistributor{GID, PID, LID} where GID <: Integer where PID <: Integer where LID <: Integer
     SerialDistributor{GID, PID, LID}()
 end
+
+getComm(::SerialDistributor{GID, PID, LID}) where {GID, PID, LID} = SerialComm{GID, PID, LID}()