C# - Added Dynamic Type and var implicit type

`var` and `dynamic` are used in variable definitions in C#. Added them for Crayon support
C# - Added aynsc and await reserved words

This should be a partial solution / low hanging fruit for #149
C# - Added get and set keywords

In C#, you can write something like:

    public class SomeClass
    {
        int _somevalue;
        public int SomeProperty
        {
            get
            {
                return _someValue;
            }
            set
            {
                _someValue = value;
            }
        }
    }

This adds support for `get` and `set` in this example.

Improves the problem explained in #149 as well.
Added new theme.
Added backwards compatibility for Wordpress 3.8.
Merge pull request #169 from Meligy/patch-1

C# - Added Dynamic Type and var implicit type
Merge pull request #171 from Meligy/patch-3

C# - Added get and set keywords
Merge pull request #170 from Meligy/patch-2

C# - Added aynsc and await reserved words
Added changelog info.
Merge remote-tracking branch 'upstream/master'
Synced with upstream; moved C#:async to modifier.txt