Fix typos in comments and assertion messages

Closes https://github.com/wxWidgets/wxWidgets/pull/1596

include/wx/gtk1/window.h

@@ -149,8 +149,8 @@ public:
     virtual void ApplyToolTip( GtkTooltips *tips, const wxChar *tip );
 #endif // wxUSE_TOOLTIPS
 
-    // Call after modifing the value of m_hAdjust or m_vAdjust to bring the
-    // scrolbar in sync (this does not generate any wx events)
+    // Call after modifying the value of m_hAdjust or m_vAdjust to bring the
+    // scrollbar in sync (this does not generate any wx events)
     void GtkUpdateScrollbar(int orient);
 
     // Called from GTK signal handlers. it indicates that

include/wx/memory.h

@@ -264,7 +264,7 @@ public:
     static wxMemStruct * GetHead () { return m_head; }
     static wxMemStruct * GetTail () { return m_tail; }
 
-    // Set the list sentinals.
+    // Set the list sentinels.
     static wxMemStruct * SetHead (wxMemStruct * st) { return (m_head = st); }
     static wxMemStruct * SetTail (wxMemStruct * st) { return (m_tail = st); }
 

src/gtk/dcclient.cpp

@@ -320,8 +320,8 @@ wxWindowDCImpl::wxWindowDCImpl( wxDC *owner, wxWindow *window ) :
 
     SetUpDC();
 
-    /* this must be done after SetUpDC, bacause SetUpDC calls the
-       repective SetBrush, SetPen, SetBackground etc functions
+    /* this must be done after SetUpDC, because SetUpDC calls the
+       respective SetBrush, SetPen, SetBackground etc functions
        to set up the DC. SetBackground call m_owner->SetBackground
        and this might not be desired as the standard dc background
        is white whereas a window might assume gray to be the

src/gtk1/dcclient.cpp

@@ -318,8 +318,8 @@ wxWindowDCImpl::wxWindowDCImpl(wxDC *owner, wxWindow *window)
 
     SetUpDC();
 
-    /* this must be done after SetUpDC, bacause SetUpDC calls the
-       repective SetBrush, SetPen, SetBackground etc functions
+    /* this must be done after SetUpDC, because SetUpDC calls the
+       respective SetBrush, SetPen, SetBackground etc functions
        to set up the DC. SetBackground call m_owner->SetBackground
        and this might not be desired as the standard dc background
        is white whereas a window might assume gray to be the

src/html/htmlcell.cpp

@@ -96,7 +96,7 @@ wxHtmlCell::~wxHtmlCell()
     delete m_Link;
 }
 
-// Update the descent value when whe are in a <sub> or <sup>.
+// Update the descent value when we are in a <sub> or <sup>.
 // prevbase is the parent base
 void wxHtmlCell::SetScriptMode(wxHtmlScriptMode mode, long previousBase)
 {

src/motif/xmcombo/combobox.doc

@@ -201,7 +201,7 @@ Motif 2.0 will have one - whow! after many years, the OSF folk got it!)
 P.S.: This software is Free Software. Please refer to the file
       COPYING, which you should have received together this
       file and the source code of the combo box widget.
-      However if you find this widget to be usefull, you are encouraged
+      However if you find this widget to be useful, you are encouraged
       to donate a reasonable amount to a charitable institution --
       there are enough people out there who need help! Sometimes I got
       the strong impression that programmers tend to get lost in their

src/osx/core/bitmap.cpp

@@ -401,7 +401,7 @@ void *wxBitmapRefData::BeginRawAccess()
 
 #if wxOSX_USE_ICONREF
     wxASSERT_MSG( m_iconRef == NULL ,
-                 wxT("Currently, modifing bitmaps that are used in controls already is not supported") ) ;
+                 wxT("Currently, modifying bitmaps that are used in controls already is not supported") ) ;
 #endif
 
     ++m_rawAccessCount ;

src/x11/dcclient.cpp

@@ -203,8 +203,8 @@ wxWindowDCImpl::wxWindowDCImpl( wxDC* owner, wxWindow *window )
 
     SetUpDC();
 
-    /* this must be done after SetUpDC, bacause SetUpDC calls the
-       repective SetBrush, SetPen, SetBackground etc functions
+    /* this must be done after SetUpDC, because SetUpDC calls the
+       respective SetBrush, SetPen, SetBackground etc functions
        to set up the DC. SetBackground call m_window->SetBackground
        and this might not be desired as the standard dc background
        is white whereas a window might assume gray to be the