tripEstimation maintenance

This is intended to snapshot tripEstimation at the unreleased r-forge version 0.0-41. The latest on CRAN is 0.0-40 and still Imports rgdal, which created difficulties for some projects.

The intention is to port the core code to a temporary project and either rebuild tripEstimation from that or recreate the functionality in a new project. Having the CRAN-release package hosted on r-forge via Subversion was creating difficulties in moving to GIT.