mfenniak/rethinkdb-net — pull request #127 by jweber (2013-09-10 08:14:22+00:00)
Title: Added support for the Parameter ExpressionType in SingleParameterLambda

I'm assuming support for the Parameter type should be in place for this method. I was trying to run a ReQL query similar to:
```
r.db('db').table('table')
.concatMap(function(b) { return b('tags') })
.groupedMapReduce(
function(t) { return t },
function() { return 1 },
function(x,y) { return x.add(y) })
```
but was encountering the following exception:
`System.InvalidOperationException : Failed to perform client-side evaluation of expression tree node; often this is caused by refering to a server-side variable in a node that is only supported w/ client-side evaluation`

I added a test that mimics what I was trying to accomplish. Thanks!