expression grammara - add log function

include/mapnik/expression_grammar_x3_def.hpp

@@ -227,6 +227,7 @@ namespace mapnik { namespace grammar {
                 ("tan",  tan_impl())
                 ("atan", atan_impl())
                 ("exp",  exp_impl())
+                ("log",  log_impl())
                 ("abs",  abs_impl())
                 ("length",length_impl())
                 ;

include/mapnik/function_call.hpp

@@ -47,7 +47,6 @@ struct exp_impl
     {
         return std::exp(val.to_double());
     }
-
 };
 
 // log
@@ -58,7 +57,6 @@ struct log_impl
     {
         return std::log(val.to_double());
     }
-
 };
 
 // sin