Drop including (unused) malloc.h

malloc.h used to define malloc hooks API, which have been deprecated
and marked volatile in (e)glibc 2.14. Malloc hooks, nor other special
facilities defined in malloc.h, appear to not be used, thus this
include is redundant.

http://sourceware.org/ml/libc-alpha/2011-05/msg00103.html
Merge pull request #5 from xnox/drop-malloc.h

Drop including (unused) malloc.h
Add an explicit test for handling a NULL array in dbus calls.
Update dbus code generator to allow for empty lists for type 'as'

This drops the != NULL check for NULL terminated arrays and moves the
iteration loop inside an 'if' statement.
Merge pull request #4 from xnox/fix-dbus

Update dbus code generator to allow for empty lists for type 'as'
Merge branch 'master' of https://github.com/keybuk/libnih