remove rcharts from egs, description, etc.

[sckott]

These have Suggests or Enhances in non-mainstream repositories as listed
below. The CRAN Policy has

Packages on which a CRAN package depends should be available from a
mainstream repository: if any mentioned in ‘Suggests’ or ‘Enhances’
fields are not from such a repository, where to obtain them at a
repository should be specified in an ‘Additional_repositories’ field
of the DESCRIPTION file (as a comma-separated list of repository URLs)
or for other means of access, described in the ‘Description’ field.

(where in any case, the packages mentioned should be available for
installation using the standard R package management tools).

Can you pls update your packages accordingly?

Ideally, all Suggests or Enhances in non-mainstream repositories would
be available from repositories in Additional_repositories fields. In
most cases, the mentioned packages seem to be available from either
R-Forge or Omegahat, so updating is straightforward.