Fixed VC6-specific compile errors

stepmania/src/BitmapText.cpp

@@ -216,7 +216,7 @@ void BitmapText::SetText( CString sText, bool DoSubst )
 	m_iLineWidths.clear();
 	m_iLineHeights.clear();
 
-	lstring s; s.push_back('\n');
+	lstring s; s+='\n';
 	split(CStringToLstring(sText), s, m_szTextLines, false);
 	
 	/* calculate line lengths and widths */

stepmania/src/Font.cpp

@@ -209,11 +209,13 @@ Font::Font()
 
 Font::~Font()
 {
-	for(unsigned i = 0; i < pages.size(); ++i)
+	unsigned i;
+
+	for(i = 0; i < pages.size(); ++i)
 		delete pages[i];
 
 	/* Free any fonts that we merged into us. */
-	for(unsigned i = 0; i < merged_fonts.size(); ++i)
+	for(i = 0; i < merged_fonts.size(); ++i)
 		FONT->UnloadFont(merged_fonts[i]);
 }
 

stepmania/src/RageUtil.cpp

@@ -915,9 +915,9 @@ lstring CStringToLstring(const CString &str)
 	{
 		longchar c = utf8_get_char (ptr);
 		if(c == -1)
-			ret.push_back(INVALID_CHAR);
+			ret += INVALID_CHAR;
 		else
-			ret.push_back(c);
+			ret += c;
 		ptr = utf8_find_next_char (ptr, end);
 	}