Adding .editorconfig to repository.

.editorconfig

+# see http://editorconfig.org/ for docs on this file
+
+root = true
+
+[*]
+# help with sharing files across os's (i.e. network share or through local vm)
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+# formattable file extensions (keep in sync with format.ini from unity-meta repo)
+#
+# Note: We need to split the formattable files configs into shorter duplicate entries (logically grouped)
+# due to known issue in VS editorconfig extension where there is a limit of 51 characters (empirically determined).
+# see: https://github.com/editorconfig/editorconfig-visualstudio/issues/21
+#
+## uncrustify
+[*.{c,h,cpp,hpp,m,mm,cc,cs}]
+indent_style = space
+indent_size = 4
+
+## generic formatter (shaders)
+[*.{cg,cginc,glslinc,hlsl,shader,y,ypp,yy}]
+indent_style = space
+indent_size = 4
+
+## generic formatter (misc)
+[*.{asm,s,S,pch,pchmm,java,sh,uss}]
+indent_style = space
+indent_size = 4
+
+## perltidy
+[*.{pl,pm,t,it}]
+indent_style = space
+indent_size = 4
+
+## unity special
+[*.{bindings,mem.xml}]
+indent_style = space
+indent_size = 4
+
+# other filetypes we want to overwrite default configuration to preserve the standard
+[{Makefile,makefile}]
+# TAB characters are part of the Makefile format
+indent_style = tab
+
+[*.{md,markdown}]
+# trailing whitespace is significant in markdown (bad choice, bad!)
+trim_trailing_whitespace = false
+
+[*.{json,asmdef}]
+indent_style = space
+# seems to be more common
+indent_size = 2
+
+# keep these and the VS stuff below in sync with .hgeol's CRLF extensions
+[*.{vcproj,bat,cmd,xaml,tt,t4,ttinclude}]
+end_of_line = crlf
+
+# this VS-specific stuff is based on experiments to see how VS will modify a file after it has been manually edited.
+# the settings are meant to closely match what VS does to minimize unnecessary diffs. this duplicates some settings in *
+# but let's be explicit here to be safe (in case someone wants to copy-paste this out to another .editorconfig).
+[*.{vcxproj,vcxproj.filters,csproj,props,targets}]
+indent_style = space
+indent_size = 2
+end_of_line = crlf
+charset = utf-8-bom
+trim_trailing_whitespace = true
+insert_final_newline = false
+[*.{sln,sln.template}]
+indent_style = tab
+indent_size = 4
+end_of_line = crlf
+trim_trailing_whitespace = true
+insert_final_newline = false