Inverted blocks appears to not support {{else}}

[ticklemepierce]

Issue is with demonstrated with the following code:

compiler = Compiler()

source = u"{{^if image}}no image{{else}}image{{/if}}"

template = compiler.compile(source)

output = template({
    'image': 'image'
})

print output

Should print "image", however, it prints nothing as the case cannot be handled.