Fix assorted typos.

From https://sourceforge.net/p/swig/patches/332/ and some others too.

Source/Modules/d.cxx

@@ -3625,7 +3625,7 @@ private:
       // If the import statement has been found in the target string, we have to
       // check if the previous import was static, which would lead to problems
       // if this import is not.
-      // Thus, we check if the seven characters in front of the occurence are
+      // Thus, we check if the seven characters in front of the occurrence are
       // »static «. If the import string passed is also static, the checks fail
       // even if the found statement is also static because the last seven
       // characters would be part of the previous import statement then.

Source/Modules/lua.cxx

@@ -113,7 +113,7 @@ private:
   String *s_var_tab;		// table of global variables
   String *s_const_tab;		// table of global constants
   String *s_methods_tab;	// table of class methods
-  String *s_attr_tab;		// table of class atributes
+  String *s_attr_tab;		// table of class attributes
   String *s_luacode;		// luacode to be called during init
   String *s_dot_get;            // table of variable 'get' functions
   String *s_dot_set;            // table of variable 'set' functions