Segregated symbols into 5 separate namespaces

The different namespaces are:

  Function      Value expression functions, which receive a "context"
  Option        Command-line options
  Precommand    Commands which are invoked before reading the journal
  Command       Commands which are invoked after reading the journal
  Directive     Directives that occur at column 0 in a data file

This greatly eases the ability for Python uses to add intercept hooks to
change how the basic Ledger module functions.  An example of what should
be possible soon:

  import ledger

  def my_foo_handler(value):
      print "--foo received:", value

  ledger.add_handler(ledger.Option, "foo=", my_foo_handler)

1 files changed, 1 insertions, 1 deletions

diff --git a/src/py_value.cc b/src/py_value.cc
index 86311736..eec3b833 100644
--- a/src/py_value.cc
+++ b/src/py_value.cc
@@ -51,7 +51,7 @@ namespace {
   {
     if (value.is_scope()) {
       if (scope_t * scope = value.as_scope())
-	return expr_t(scope->lookup(name), scope);
+	return expr_t(scope->lookup(symbol_t::FUNCTION, name), scope);
     }
     throw_(value_error, _("Cannot lookup attributes in %1") << value.label());
     return expr_t();