Remove alias code from prefilter

IPython/core/prefilter.py

@@ -488,22 +488,6 b' class AutoMagicChecker(PrefilterChecker):'
         return self.prefilter_manager.get_handler_by_name('magic')
 
 
-class AliasChecker(PrefilterChecker):
-
-    priority = Integer(800, config=True)
-
-    def check(self, line_info):
-        "Check if the initital identifier on the line is an alias."
-        # Note: aliases can not contain '.'
-        head = line_info.ifun.split('.',1)[0]
-        if line_info.ifun not in self.shell.alias_manager \
-               or head not in self.shell.alias_manager \
-               or is_shadowed(head, self.shell):
-            return None
-
-        return self.prefilter_manager.get_handler_by_name('alias')
-
-
 class PythonOpsChecker(PrefilterChecker):
 
     priority = Integer(900, config=True)
@@ -591,20 +575,6 b' class PrefilterHandler(Configurable):'
         return "<%s(name=%s)>" % (self.__class__.__name__, self.handler_name)
 
 
-class AliasHandler(PrefilterHandler):
-
-    handler_name = Unicode('alias')
-
-    def handle(self, line_info):
-        """Handle alias input lines. """
-        transformed = self.shell.alias_manager.expand_aliases(line_info.ifun,line_info.the_rest)
-        # pre is needed, because it carries the leading whitespace.  Otherwise
-        # aliases won't work in indented sections.
-        line_out = '%sget_ipython().system(%r)' % (line_info.pre_whitespace, transformed)
-
-        return line_out
-
-
 class MacroHandler(PrefilterHandler):
     handler_name = Unicode("macro")