*) Change FOOTPRINT_LIST::ReadFootprintFiles( FP_LIB_TABLE*, const wxString*)

To use multiple working threads.  This entailed adding KiCad typedefs:
*) Add typedefs for MUTEX and MUTLOCK which mask the actual choices for the project.
*) Add FOOTPRINT_LIST::DisplayErrors( wxWindow* ) which is a single strategy for
   showing aggregated load errors.  Although what's there is only scaffolding
   and needs a volunteer who knows HTML pretty well.
*) Ensure all callers of ReadFootprintFiles() use the new DisplayErrors() function.   
*) Push utf8.cpp and utf8.h into common library for open use.

common/html_messagebox.cpp

@@ -1,83 +1,78 @@
 #include <fctsys.h>
 #include <html_messagebox.h>
 #include <macros.h>
+#include <common.h>
 
-HTML_MESSAGE_BOX::HTML_MESSAGE_BOX( wxWindow* parent, const wxString & aTitle,
-                                      wxPoint aPos, wxSize aSize)
-    : DIALOG_DISPLAY_HTML_TEXT_BASE( parent, wxID_ANY, aTitle, aPos, aSize )
+
+HTML_MESSAGE_BOX::HTML_MESSAGE_BOX( wxWindow* parent, const wxString& aTitle,
+        wxPoint aPos, wxSize aSize) :
+    DIALOG_DISPLAY_HTML_TEXT_BASE( parent, wxID_ANY, aTitle, aPos, aSize )
 {
     ListClear();
     Center();
 }
 
+
 void HTML_MESSAGE_BOX::OnCloseButtonClick( wxCommandEvent& event )
 {
-    EndModal(0);
+    EndModal( 0 );
 }
 
 
-void HTML_MESSAGE_BOX::ListClear(void)
+void HTML_MESSAGE_BOX::ListClear()
 {
-    m_htmlWindow->SetPage(wxEmptyString);
+    m_htmlWindow->SetPage( wxEmptyString );
 }
 
-/**
- * Function ListSet
- * Add a list of items.
- * @param aList = a string containing items. Items are separated by '\n'
- */
-void HTML_MESSAGE_BOX::ListSet(const wxString &aList)
-{
-    wxArrayString* wxStringSplit( wxString txt, wxChar splitter );
 
-    wxArrayString* strings_list = wxStringSplit( aList, wxChar('\n') );
-    wxString msg = wxT("<ul>");
-    for ( unsigned ii = 0; ii < strings_list->GetCount(); ii ++ )
+void HTML_MESSAGE_BOX::ListSet( const wxString& aList )
+{
+    // wxArrayString* wxStringSplit( wxString txt, wxChar splitter );
+
+    wxArrayString* strings_list = wxStringSplit( aList, wxChar( '\n' ) );
+
+    wxString msg = wxT( "<ul>" );
+
+    for ( unsigned ii = 0; ii < strings_list->GetCount(); ii++ )
     {
-        msg += wxT("<li>");
-        msg += strings_list->Item(ii) + wxT("</li>");
+        msg += wxT( "<li>" );
+        msg += strings_list->Item( ii ) + wxT( "</li>" );
     }
-    msg += wxT("</ul>");
+
+    msg += wxT( "</ul>" );
+
     m_htmlWindow->AppendToPage( msg );
 
     delete strings_list;
 }
 
-/**
- * Function ListSet
- * Add a list of items.
- * @param aList = a wxArrayString containing items
- */
-void HTML_MESSAGE_BOX::ListSet(const wxArrayString &aList)
+
+void HTML_MESSAGE_BOX::ListSet( const wxArrayString& aList )
 {
-    wxString msg = wxT("<ul>");
-    for ( unsigned ii = 0; ii < aList.GetCount(); ii ++ )
+    wxString msg = wxT( "<ul>" );
+
+    for( unsigned ii = 0; ii < aList.GetCount(); ii++ )
     {
-        msg += wxT("<li>");
-        msg += aList.Item(ii) + wxT("</li>");
+        msg += wxT( "<li>" );
+        msg += aList.Item( ii ) + wxT( "</li>" );
     }
-    msg += wxT("</ul>");
+
+    msg += wxT( "</ul>" );
+
     m_htmlWindow->AppendToPage( msg );
 }
 
-/**
- * Function MessageSet
- * Add a message (in bold) to message list.
- * @param message = the message
- */
-void HTML_MESSAGE_BOX::MessageSet(const wxString &message)
+
+void HTML_MESSAGE_BOX::MessageSet( const wxString& message )
 {
-    wxString message_value;
-    message_value.Printf(wxT("<b>%s</b><br>"), GetChars( message ) );
+    wxString message_value = wxString::Format(
+                wxT( "<b>%s</b><br>" ), GetChars( message ) );
+
     m_htmlWindow->AppendToPage( message_value );
 }
 
-/**
- * Function AddHTML_Text
- * Add a text to message list.
- * @param message = the text to add
- */
-void HTML_MESSAGE_BOX::AddHTML_Text(const wxString &message)
+
+void HTML_MESSAGE_BOX::AddHTML_Text( const wxString& message )
 {
     m_htmlWindow->AppendToPage( message );
 }