fread option to skip lines with format errors (with warning)

[mattdowle]

Perhaps also to skip particular rows or blocks of rows for some reason (even if they are valid).
Suggested by Darius here : http://stackoverflow.com/questions/24424928/fatal-error-using-fread-in-rstudio#comment37798442_24424928

[jrowen]

I'd like to add my vote for this enhancement. I have a commonly used csv data file that includes a disclaimer line at the end of the file. Because the last line is a long text chunk without any delimiters, fread throws an error when trying to load the file. My current workaround is to use readLines to determine the number of lines in the file and then specify nrows for fread.

[karlrohe]

This would be great!

[MichaelChirico]

Solutions for some cases of this may be covered by #856