Correct spelling mistakes.

code/qcommon/unzip.h

@@ -125,8 +125,8 @@ extern int ZEXPORT unzStringFileNameCompare OF ((const char* fileName1,
                                                  int iCaseSensitivity));
 /*
    Compare two filename (fileName1,fileName2).
-   If iCaseSenisivity = 1, comparision is case sensitivity (like strcmp)
-   If iCaseSenisivity = 2, comparision is not case sensitivity (like strcmpi
+   If iCaseSenisivity = 1, comparison is case sensitivity (like strcmp)
+   If iCaseSenisivity = 2, comparison is not case sensitivity (like strcmpi
                                 or strcasecmp)
    If iCaseSenisivity = 0, case sensitivity is defaut of your operating system
     (like 1 on Unix, 2 on Windows)