refactored ZSTD_estimateDStreamSize()

now uses windowSize as argument.
Also : created ZSTD_estimateDStreamSize_fromFrame()

lib/compress/zstd_compress.c

@@ -3594,6 +3594,11 @@ ZSTD_CStream* ZSTD_createCStream(void)
     return ZSTD_createCStream_advanced(ZSTD_defaultCMem);
 }
 
+ZSTD_CStream* ZSTD_initStaticCStream(void *workspace, size_t workspaceSize)
+{
+    return ZSTD_initStaticCCtx(workspace, workspaceSize);
+}
+
 ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem)
 {   /* CStream and CCtx are now same object */
     return ZSTD_createCCtx_advanced(customMem);