Remove unneded utilities from maint/ directory.

Move an utility for found the include duplicates to maint/find-dup-includes subdirectory.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>
Reorder files in maint/ subdirectory.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>
Update the 'release procedure' file.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>