Remove stemDocumentSnowballC()

We now only stem the DTM, and anyway tm 0.5-10 uses SnowballC
by default. The examples in the docs were failing for an obscure
reason on R-Forge.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/r-temis@513 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Stop loading Tk libs on load

The libraries are provided and loaded by tcltk2,
and anyway the files were never committed to SVN.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/r-temis@514 edb9625f-4e0d-4859-8d74-9fd3b1da38cb