including file w/o overriding a __builtin__ var name default arg fails in 0.2.2 (worked in 0.1.8)

Issue #93 resolved
created an issue

If the included file specifies default page args that are the same name as a builtin then it is rendered as "builtin function" rather than the default value:

include me: test1.mako <% page args="id='foo'/>

call the included file w/o passing in "id": <% include file="test1.mako" />

The use case is thus: the included file might be rendered once per page (in which the default "id" is fine) or multiple times (in which case each "id" must be unique so in these cases a unique id is passed). This seems pythonic since, if you specify a default keyword arg, then it is the default:

def pyiscool(varname="id"): print varname

So I might invoke it as pyiscool() or pyiscool("another_id")