Reorganize r scripts, add Help files, add Home Range Analysis rscripts, add more point pattern analysis scripts

This pull request:

- Deletes "Example scripts"

- Replaces "Example scripts" with more up to date versions

- Adds general categories for r scripts: Basic statistics, Vector processing, Raster processing and Point pattern analysis

- adds help files to all r scripts

- Adds a groups of r scripts entitled "Home range analysis", that includes Kernel href, LSCV Kernel, Minimum convex polygon, single linkage cluster analysis and characteristic hull method, using adehabitatHR()

- Adds the following R scripts contributed by Yury Ryabov ( riabovvv(at)gmail.com ): Advanced raster histogram, Monte carlo spatial randomness, Relative distribution (distance covariate), Relative distribution (raster covariate),