Merge pull request #18 from mikepurvis/hydro-devel

Globbing for <xacro:include>
fix setting of _xacro_py CMake var

Fixes #16
fix evaluation of integers in if statements

also added a unit test, fixes #15
Add roslint target to xacro; two whitespace fixes so that it passes.
Remove the roslint_python glob, use the default one.
Merge pull request #21 from mikepurvis/with-roslint

Add roslint target to xacro; two whitespace fixes so that it passes.
Installed xacro relocatable fix.