* Makefile.in: Use DEP_INCLUDE.

* tools/Makefile.in: Likewise.
* testsuite/Makefile.in: Likewise.
* examples/Makefile.in: Likewise.

Rev: src/nettle/ChangeLog:1.306
Rev: src/nettle/Makefile.in:1.14
Rev: src/nettle/examples/Makefile.in:1.9
Rev: src/nettle/testsuite/Makefile.in:1.9
Rev: src/nettle/tools/Makefile.in:1.10