Updates for CRAN comments

[barnett11]

Please always explain all acronyms in the description text. -> 'STDM'

The Description field is intended to be a (one paragraph) description of
what the package does and why it may be useful. Please add more details
about the package functionality and implemented methods in your
Description text.

Please do not start the description with "Functions for", "This
package", package name, title or similar.'

Please do not modifiy the .GlobalEnv. This is not allowed by the CRAN
policies. -> inst/doc/examplemodular.R; inst/doc/modular.R