[update] remove unused variables

As a side note, remove AS_INIT from configure.ac, becuase it is already
called by AC_INIT, and reiniting it called an infinite loop of the
script calling itself.

Signed-off-by: Shahbaz Youssefi <ShabbyX@gmail.com>
[feature] add duplicate function to structures

Signed-off-by: Shahbaz Youssefi <ShabbyX@gmail.com>