data tree DOC update structures description and do some changes in API
diff --git a/Doxyfile b/Doxyfile
index c503f4c..c9d0b8f 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -381,7 +381,7 @@
 # Man pages) or section (for LaTeX and RTF).
 # The default value is: NO.
 
-INLINE_SIMPLE_STRUCTS  = NO
+INLINE_SIMPLE_STRUCTS  = YES
 
 # When TYPEDEF_HIDES_STRUCT tag is enabled, a typedef of a struct, union, or
 # enum is documented as struct, union, or enum with the name of the typedef. So