Added 'filter' support to position function; Made sure sort script can depend on the value of the field itself.

Cleaned up some things, why is a blank image not thread safe?

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@548 0fc631ac-6414-0410-93d0-97cfa31319b6

src/render/text/element.cpp

@@ -145,7 +145,7 @@ struct TextElementsFromString {
 					// ignore other tags
 				}
 			} else {
-				if (c == _('\1')) c = _('<'); // unescape
+				c = untag_char(c); // unescape
 				// A character of normal text, add to the last text element (if possible)
 				SimpleTextElement* e = nullptr;
 				if (!te.elements.empty()) e = dynamic_cast<SimpleTextElement*>(te.elements.back().get());