Add line numbers and file names to eval calls.

Closes sass#528

lib/sass/callbacks.rb

@@ -48,7 +48,7 @@ def clear_callbacks!
     # @param name [Symbol] The name of the callback
     # @return [void]
     def define_callback(name)
-      class_eval <<RUBY
+      class_eval <<RUBY, __FILE__, __LINE__ + 1
 def on_#{name}(&block)
   @_sass_callbacks ||= {}
   (@_sass_callbacks[#{name.inspect}] ||= []) << block

lib/sass/logger/log_level.rb

@@ -36,14 +36,14 @@ def log_level(name, options = {})
         end
 
         def define_logger(name, options = {})
-          class_eval %Q{
+          class_eval <<-RUBY, __FILE__, __LINE__ + 1
             def #{name}(message)
               #{options.fetch(:to, :log)}(#{name.inspect}, message)
             end
-          }
+          RUBY
         end
       end
 
     end
   end
-end
+end

lib/sass/script/parser.rb

@@ -203,7 +203,7 @@ def associative?(op)
         # sub is the name of the production beneath it,
         # and ops is a list of operators for this precedence level
         def production(name, sub, *ops)
-          class_eval <<RUBY
+          class_eval <<RUBY, __FILE__, __LINE__ + 1
             def #{name}
               interp = try_ops_after_interp(#{ops.inspect}, #{name.inspect}) and return interp
               return unless e = #{sub}
@@ -223,7 +223,7 @@ def #{name}
         end
 
         def unary(op, sub)
-          class_eval <<RUBY
+          class_eval <<RUBY, __FILE__, __LINE__ + 1
             def unary_#{op}
               return #{sub} unless tok = try_tok(:#{op})
               interp = try_op_before_interp(tok) and return interp