Better statement separating regex

Split on lines starting with - and being surrounded by at least on
newline before, but arbitrary amounts of newlines before and after.
The dash can be followed by anything (having seen both '}' and 'ä' in
real examples)

lib/cmxl.rb

@@ -11,7 +11,7 @@ def self.config
     @config
   end
   @config = {
-    statement_separator: /\n-\s*\n/m,
+    statement_separator: /\R+-[^\n\r]*\R*/m,
     raise_line_format_errors: true,
     strip_headers: false
   }