added constant ZSTD_WINDOWLOG_LIMIT_DEFAULT

answering #1407.

Also : removed obsolete function ZSTD_setDStreamParameter()
which could only be used with one parameter (DStream_p_maxWindowSize).
Now replaced by ZSTD_DCtx_setWindowSize() (which exists since a few revisions)

lib/common/zstd_internal.h

@@ -78,7 +78,6 @@ static const U32 repStartValue[ZSTD_REP_NUM] = { 1, 4, 8 };
 #define BIT0   1
 
 #define ZSTD_WINDOWLOG_ABSOLUTEMIN 10
-#define ZSTD_WINDOWLOG_DEFAULTMAX 27 /* Default maximum allowed window log */
 static const size_t ZSTD_fcs_fieldSize[4] = { 0, 2, 4, 8 };
 static const size_t ZSTD_did_fieldSize[4] = { 0, 1, 2, 4 };