ros/xacro — pull request #40 by rhaschke (2014-06-26 23:02:36+00:00)
Title: allow for recursive evaluation of properties

Recursive evaluation of properties, i.e.
`
`

should work. Currently, `${a2}` literally gives `${2*a}` instead of `84`.
This patch adds this feature, correctly catching recursive definitions.
Proper functioning is checked by two new test cases.