Better handling of newlines and indentation for element content text

FormattingXMLStreamWriter.writeCharacters(String) always puts element content text on a new line, indented. This increases document size and makes it difficult for AS7 to write out a document that doesn't have unnecessary whitespace changes versus the original version of the document.

A couple of possibilities:

1) Have writeCharacters(String) only put in a new line and indent if the given text itself has a new line (i.e. format multiline text, but leave single line text on a single line)
2) Have writers use the writeCharacters(char[] chars) method, but adjust the element close behavior so the closing element tag is only indented and put on a new line if the content text was.

IMO the 2nd change should be made in any case, as the existing behavior results in output like this if the writeCharacters(char[] chars) method is used:

<element>thetext
</element>