added highlighting on wrong line continuitation

in macrodefinitions line continuitations using '\' are easy to make wrong if there is a space beyond the '\'.
If one doesn't see this, this is a ugly source of errors.
This patch shows the error cleary by highlighting any between after '\' and '\n'
incorporating Abusalimov's comments
Merge #7 (highlight trailing spaces after line continuitation)
Merge branch 'andik-master'