title: Option to limit displayed length of text strings in data.tables
body: <p>Some columns in data.tables can have content that is quite long (nchar(.) is large). This can sometimes make it difficult to inspect the whole data.table in R, since it will break after the wide columns. At the same time the information stored in the wide column may still be needed, so simply doing something along the lines of <code>DT[, long_strings := substr(long_strings, 1, max_length)]</code> is not a good solution.</p>
  <p>Is there an option with which the display length of text can be controlled, so to make text columns in data.table be displayed denser than they are?</p>