Removed support for multi-line text drawing

When trying to test the previous commit, I couldn't find any place in
the application where strings containing newlines are drawn. So I'm
assuming this is an unnecessary feature, until someone comes up with
a test case proving otherwise.

Yeah, I'm too lazy to review all the code that draws text...

src/font.cpp

@@ -59,30 +59,7 @@ int Font::getTextWidth(const char *text)
 	else return 1;
 }
 
-void Font::write(Surface *surface, const string &text,
+void Font::write(Surface *surface, std::string const& text,
-			int x, int y, HAlign halign, VAlign valign)
-{
-	if (!font) {
-		return;
-	}
-
-	size_t pos = text.find('\n', 0);
-	if (pos == string::npos) {
-		writeLine(surface, text, x, y, halign, valign);
-	} else {
-		size_t prev = 0;
-		do {
-			writeLine(surface, text.substr(prev, pos - prev),
-					x, y, halign, valign);
-			y += lineSpacing;
-			prev = pos + 1;
-			pos = text.find('\n', prev);
-		} while (pos != string::npos);
-		writeLine(surface, text.substr(prev), x, y, halign, valign);
-	}
-}
-
-void Font::writeLine(Surface *surface, std::string const& text,
 				int x, int y, HAlign halign, VAlign valign)
 {
 	if (!font) {

src/font.h

@@ -41,9 +41,6 @@ public:
 private:
 	Font(TTF_Font *font);
 
-	void writeLine(Surface *surface, std::string const& text,
-				int x, int y, HAlign halign, VAlign valign);
-
 	TTF_Font *font;
 	int lineSpacing;
 };