Fix minor typos in comments.

include/wx/propgrid/propgrid.h

@@ -281,7 +281,7 @@ wxPG_EX_HELP_AS_TOOLTIPS            = 0x00010000,
 /** Prevent TAB from focusing to wxButtons. This behaviour was default
     in version 1.2.0 and earlier.
     NOTE! Tabbing to button doesn't work yet. Problem seems to be that on wxMSW
-      atleast the button doesn't properly propagate key events (yes, I'm using
+      at least the button doesn't properly propagate key events (yes, I'm using
       wxWANTS_CHARS).
 */
 //wxPG_EX_NO_TAB_TO_BUTTON            = 0x00020000,

src/propgrid/manager.cpp

@@ -1985,7 +1985,7 @@ void wxPropertyGridManager::OnResize( wxSizeEvent& WXUNUSED(event) )
 
 void wxPropertyGridManager::OnMouseEntry( wxMouseEvent& WXUNUSED(event) )
 {
-    // Correct cursor. This is required atleast for wxGTK, for which
+    // Correct cursor. This is required at least for wxGTK, for which
     // setting button's cursor to *wxSTANDARD_CURSOR does not work.
     SetCursor( wxNullCursor );
     m_onSplitter = 0;

src/propgrid/props.cpp

@@ -1948,7 +1948,7 @@ wxValidator* wxFileProperty::GetClassValidator()
 #if wxUSE_VALIDATORS
     WX_PG_DOGETVALIDATOR_ENTRY()
 
-    // Atleast wxPython 2.6.2.1 required that the string argument is given
+    // At least wxPython 2.6.2.1 required that the string argument is given
     static wxString v;
     wxTextValidator* validator = new wxTextValidator(wxFILTER_EXCLUDE_CHAR_LIST,&v);