Handle modulo operator without spaces

`x %3` should be interpreted as a modulo operation, not a parameter
marker.

Co-authored-by: Rocky Meza <rmeza@fusionbox.com>

Improved sqlparse.utils.split_unquoted_newlines()

I've modified this function to use a regular expression for most of the
work. This makes it much, much faster, especially for large queries.

Fix SerializerUnicode to split unquoted newlines

This provides a fix to issue #131. The `split_unquoted_newlines()`
function added to the utils module handles the splitting of the string
by performing a simple iteration of the string passed in and splitting
on unquoted CR, LF, or CR+LFs as they are found.