Add .editorconfig based on Roslyn's

Should have sane defaults, we will tweak as necessary.

Author: angularsen

.editorconfig

@@ -0,0 +1,81 @@
+# EditorConfig is awesome:http://EditorConfig.org
+# Based on: https://raw.githubusercontent.com/dotnet/roslyn/master/.editorconfig
+
+# top-most EditorConfig file
+root = true
+
+# Don't use tabs for indentation.
+[*]
+indent_style = space
+# (Please don't specify an indent_size here; that has too many unintended consequences.)
+
+# Code files
+[*.{cs,csx,vb,vbx}]
+indent_size = 4
+insert_final_newline = true
+charset = utf-8-bom
+
+# Xml project files
+[*.{csproj,vbproj,vcxproj,vcxproj.filters,proj,projitems,shproj}]
+indent_size = 2
+
+# Xml config files
+[*.{props,targets,ruleset,config,nuspec,resx,vsixmanifest,vsct}]
+indent_size = 2
+
+# JSON files
+[*.json]
+indent_size = 2
+
+# Dotnet code style settings:
+[*.{cs,vb}]
+# Sort using and Import directives with System.* appearing first
+dotnet_sort_system_directives_first = true
+# Avoid "this." and "Me." if not necessary
+dotnet_style_qualification_for_field = false:suggestion
+dotnet_style_qualification_for_property = false:suggestion
+dotnet_style_qualification_for_method = false:suggestion
+dotnet_style_qualification_for_event = false:suggestion
+
+# Use language keywords instead of framework type names for type references
+dotnet_style_predefined_type_for_locals_parameters_members = true:suggestion
+dotnet_style_predefined_type_for_member_access = true:suggestion
+
+# Suggest more modern language features when available
+dotnet_style_object_initializer = true:suggestion
+dotnet_style_collection_initializer = true:suggestion
+dotnet_style_coalesce_expression = true:suggestion
+dotnet_style_null_propagation = true:suggestion
+dotnet_style_explicit_tuple_names = true:suggestion
+
+# CSharp code style settings:
+[*.cs]
+# Prefer "var" everywhere
+csharp_style_var_for_built_in_types = true:suggestion
+csharp_style_var_when_type_is_apparent = true:suggestion
+csharp_style_var_elsewhere = true:suggestion
+
+# Prefer method-like constructs to have a block body
+csharp_style_expression_bodied_methods = false:none
+csharp_style_expression_bodied_constructors = false:none
+csharp_style_expression_bodied_operators = false:none
+
+# Prefer property-like constructs to have an expression-body
+csharp_style_expression_bodied_properties = true:none
+csharp_style_expression_bodied_indexers = true:none
+csharp_style_expression_bodied_accessors = true:none
+
+# Suggest more modern language features when available
+csharp_style_pattern_matching_over_is_with_cast_check = true:suggestion
+csharp_style_pattern_matching_over_as_with_null_check = true:suggestion
+csharp_style_inlined_variable_declaration = true:suggestion
+csharp_style_throw_expression = true:suggestion
+csharp_style_conditional_delegate_call = true:suggestion
+
+# Newline settings
+csharp_new_line_before_open_brace = all
+csharp_new_line_before_else = true
+csharp_new_line_before_catch = true
+csharp_new_line_before_finally = true
+csharp_new_line_before_members_in_object_initializers = true
+csharp_new_line_before_members_in_anonymous_types = true