Clarifying error message
Fixing order of arguments when building tractor executable
Fixing minor memory leak
Checking that parallelisation factor is sensible; avoiding use of math.h functions for portability
Using R CMD LINK for tractor binary
Making bootstrap string global
Trying to avoid a memory error
Making linear reg test more permissive still
Using native tracker in places where there is no Tracker option (HNT, pnt-viz)
Updating version numbers
Updating docs
Merge branch '2.4'