Add support for strings to c# KowhaiTree
Add support for strings to c# KowhaiTree

+ display strings (char arrays) in KowhaiTree. These are shown
differently from other arrays as they have no leaf nodes, the whole
string is just shown like a node that is not an array
+ allow edit of strings in KowhaiTree like other nodes.

djpnewton/kowhai,djpnewton/kowhai,djpnewton/kowhai,djpnewton/kowhai,djpnewton/kowhai