Remove Buildable Artifacts from the Github (especially binaries)

[jrawbits]

The Github should not include versioned files that are rebuilt when RStudio package build or VE-Installer are used to create or install the package. This issue needs to be resolved in two steps:

1. Use 'git rm' to remove files that are built when packages are constructed, but carefully keep and perhaps relocate files (like "VELandUse::data/HhAllocationModelCoeff.rda") that are provided from outside, rather than built internally. The VELandUse file should be placed in inst/extdata (so end users can inspect it).

2. Relaunch VisionEval-dev and VisionEval repositories with pruned history to avoid having to download gigabytes of obsolete data files when cloning the repository. Alternatively, encourage people to clone the repository with a limited --depth parameter.

[jrawbits]

I'm going to close this issue: we still have much too much such "history" (so the clone of a repository is really time-consuming as all the junk that should never have been included gets downloaded). We'll come back to paring down the history some day. For now, the current build process makes sure most such things are not included.