accept tf_timeout < 0 to ignore timeout

[knorth55]

this PR change to accept tf_timeout param -1 to ignore transformation timeout check.
this is useful when we use tf_static_transformer for debugging.

[corot]

Why not just passing a very big value?
And can u actually have a negative ros::Duration?

I would instead reconsider your use case; I'm not at all convince about the need of this change

[knorth55]

tf_static_publisher uses the first timestamp when node starts.
we run robots for weeks, so the duration will be super large.
so i use -1 as tf.lookUTransform

[knorth55]

we dont use map and amcl, so we directly connect odom and map by tf_static_publisher.

[corot]

tf_static_publisher uses the first timestamp when node starts. we run robots for weeks, so the duration will be super large. so i use -1 as tf.lookUTransform

Yes, static tfs only need to be published once, but tf library considers them as always available, at any timestamp.
So that should not require this PR. You may have some other hidden problem in the code