More detailed exception message from pipeline.
REFACTOR: LINQify binding `ValueFromPipeline` parameter.
Improve more `ToString()` for debugging.
TEST: Issue #20 - Goal tests for pipelining.
`ObjectStream.ToString()` for debugging
Issue #20 - Unroll arrays in pipeline.

Otherwise the whole array gets passed as a single element in the pipeline.

This exposes a bug in `PipelineProcessor.Execute`. Now an array of 3
elements will cause the first element to be streamed 4 times.
REFACTOR: `WriteHostCommand`: Extract Method and more
Fix WriteHost on an array
Implement `$null`
Issue #78 - `Sort-Host` - now with acutal sorting!
Issue #20: Fix streaming multiple items

Before, a stream of objects would appear as the first object repeated the wrong number of times.

    PASH> 1..2 | sort-object
    1
    1
    PASH> 1..3 | sort-object
    1
    1
    1
    1
    PASH> 1..4 | sort-object
    1
    1
    1
    1
    1
    1
    1
    1

Now we get the right results:

    PASH> 3..1 | sort-object
    1
    2
    3
Issue #78 - Fix sorting of integers

Previously the comparator would return `0` on unrecognized inputs,
producing unpredictable sort results.
TEST: Move sort tests to their own class

This diff looks better with `git diff -w`
Remove empty ctor
REFACTOR: supply a custom comparator in `Sort-Object`
Sort by property (fixed #28)
Merge pull request #91 from JayBazuzi/issue-78-sort-object2

Fix #78 - Sort-Object is no longer completely broken