Update grammar for real literals.

Allow capital E for the exponent:
    1.2E4

Allow multiple digits for the exponent:
    1.2e45
Implement simple real literals.

The following simple real literals are supported:

    1.2
    .4
    123.456e-2
    123.456e-231
    123.456E-231
    3.45e3
    32.2e+36

The following do not work in Pash, but do work with Microsoft's
PowerShell:

    3.e3
    32.e+12
    1.

It looks like these are missing from the official PowerShell grammar
although there is an example of one of them in the PowerShell spec.
ReferenceTests for PSObject reflection properties
PSObject member reflection capabilities
Add-Member cmdlets, related tests
Member access and invocation abstraction via PSObject

The new capabilities of PSObject are now used to access properties,
fields and methods of any object by abstracting the access through
PSObject.
The current implementation lacks support for static members and will
be added in the next commit.
This means the new tests are all working, but some old aren't with
this commit.
Support for static members
Abstraction of PSMethodInfo

Implementation is now in PSMethod as intended by the API specification.
Support for overloaded method invocation
Fixed introduced error on assignments with operaors
Fixed and enabled some tests that work now
Added ObjectCommandTests to PowershellReferenceTests project and fixed incompatibilities
Made test explicit again which didn't work correct.
Refactoring: Fixed typo
Internal Array support

Previously arrays were treated as Collections, however, this isn't PS conform.
Now, arrays are real C# object[] arrays, so properties like @(1,2,3).Length are
available.
Enabled some tests that work now
Enabled some tests that worked, minor fixes
Fix for accessing properties of interfaces implemented by interfaces
Minor fixes
Fix: Invocation of methods in old mono versions

Old mono versions didn't support optional "params" parameters
when invoking methods using reflection.