NLSR

Presently, the default NLSR Hello data freshness is set to a default of 10s. While this makes sense with current presets, there is no obvious reason for it to be this high in the first place. As timeout frequency and speed can be adjusted in a way that doesn't require hardcoding elsewhere, and there is no other obvious reason to cache this data, it seems that it would be preferable to set it to an arbitrary low value (ie 1ms) such that others don't run afoul of this in the future.