Add .editorconfig file

See http://editorconfig.org

Change-Id: Ia571ca5d53fb9f02bd8d208b922c8ec5ef1939e5
Reviewed-on: https://gerrit.libreoffice.org/28962Reviewed-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>
Tested-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>

.editorconfig

+# EditorConfig: http://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# General settings
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true
+
+# Source code files
+[*.{c,cxx,cpp,h,hxx,hpp,java,py}]
+indent_style = space
+indent_size = 4
+
+# Makefiles
+[{Makefile,*.mk}]
+indent_style = tab
+trim_trailing_whitespace = false
+
+# Patch files
+[*.patch.*]
+trim_trailing_whitespace = false