* config.make.in: Insert $(PRE_CPPFLAGS) and $(PRE_LDFLAGS) before

$(CPPFLAGS) and $(LDFLAGS). This mechanism replaces $(INCLUDES).

* examples/Makefile.in (PRE_CPPFLAGS, PRE_LDFLAGS): Use these
flags to get -I.. and -L.. early on the command line.
* testsuite/Makefile.in: Likewise
* tools/Makefile.in: Likewise.

Rev: src/nettle/ChangeLog:1.283
Rev: src/nettle/config.make.in:1.4
Rev: src/nettle/examples/Makefile.in:1.4
Rev: src/nettle/testsuite/Makefile.in:1.4
Rev: src/nettle/tools/Makefile.in:1.5