Simplify Makefile so that it does not create cf-upgrade-*.o objects.

The side-effect is that autoconf complains that we changed user-defined
variables. That is not true, because CFLAGS, CPPFLAGS, LDFLAGS are
defined by our configure.ac, because we blatantly ignore recommendations
at:

http://www.gnu.org/software/automake/manual/html_node/Flag-Variables-Ordering.html

The proper thing would be to empty the AM_CFLAGS etc options. But we
first need to refactor our configure.ac to not replace CFLAGS, and then
adjust the rest of Makefiles,
Ugly code has ugly bug.
Merge pull request #1848 from jimis/master

Windows cf-upgrade self-exec fix.
Remove lots of cruft from the default CPPFLAGS

This piece of code has been there since first git commit in 2008. It
refers to a similar bunch of code that modifies LDFLAGS, which has been
removed some time now. So lets remove this piece as well...
Indentation.
CF3_WITH_LIBRARY now takes into account previous *FLAGS

It is used for libxml2, which by defaults exists in a libxml2/
subdirectory inside include/. Thus, before calling the CF3_WITH_LIBRARY
macro, we set LIBXML2_CPPFLAGS according to the --with-libxml2 argument
together with the subdirectory prefix, and the macro is happily
detecting libxml2 like that.
CPPFLAGS now only include libutils directory. Yay!

So the last offenders modifying the environment CPPFLAGS were MYSQL,
POSTGRESQL, LIBXML2. They have been converted to have their own set of
blah_CPPFLAGS.

In addition, libxml2 includes were removed from within cf3.defs.h and
added to the source files that really need them.

As a result, cf-upgrade compilation line is at last free of dependencies:

gcc -DHAVE_CONFIG_H -I. -I../libutils   -std=gnu99  -pthread -g -O2 -g -Wall -Wno-pointer-sign -Werror=implicit-function-declaration -Wunused-parameter -g3 -O0  -MT cf-upgrade.o -MD -MP -MF .deps/cf-upgrade.Tpo -c -o cf-upgrade.o cf-upgrade.c
Statically link cfupgrade to libcompat.
Windows cf-upgrade: make re-execute command line construction more clear.
Fix order of includes.
Old autoconf does not deal well with unquoted EOLs in arguments.
Merge pull request #1850 from jimis/cfupgrade

Cleanups, including platform.h in cf-upgrade, and linking it to libcompat.
Removed PCRE dependency when linking to libutils

cf-upgrade refused to link to libutils without -lcrypto and -lpcre. The
PCRE dependency has been removed in this patch, OpenSSL dependency is
still TODO though.
Remove mandatory OpenSSL dependency from libutils.
LOUDLY mention that platform.h needs to come first.
Don't emit deprecated warning for the snprintf vs system sprintf test.
Merge pull request #1851 from jimis/cfupgrade

Remove dependencies from libutils.