#7 Build fixes

[orbea]

I combined these patches into one ticket for clarity.

https://sourceforge.net/p/libsnet/patches/4/
https://sourceforge.net/p/libsnet/patches/5/
https://sourceforge.net/p/libsnet/patches/6/

1.
To fix autoreconf-2.71 aclocal.m4 can be removed, most of it is hopelessly outdated and broken. The auto-generated aclocal.m4 by from autoconf is enough for most things.

2.
Remove hardcoded values and implement DESTDIR.

3.
* Uses pkg-config for libsasl, libssl and zlib
* Restores CHECK_PROFILED
* Removes broken legacy osx macros

The legacy CHECK_SASL, CHECK_SSL and CHECK_ZLIB macros have problems with adding hardcoded -L linker directories to the LDFLAGS which is inappropriate on modern systems. Using pkg-config avoids this problem.

When setting LIBTOOL in the environment to slibtool the profiled libraries will fail to build because of the ../ prepended to the $(LIBTOOL) variable. This was expoed when building radmind which includes libsnet as a submodule.

The legacy osx macros are totally broken and probably would need to be written from scratch. Since I don't use apple products someone else will need to work on that assuming anyone cares. For now lets just remove it.

Also see the Gentoo bug report for radmind which exposed the issues.

https://bugs.gentoo.org/779664

And the related fixes for radmind itself.

https://github.com/Radmind/radmind/pull/336
https://github.com/voretaq7/radmind/pull/1 (Gentoo uses this repo)

[orbea]

Patch # 2

[orbea]

Patch # 3

[orbea]

Patch # 4

Adds AC_ENABLE_ARG configure arguments for sasl, ssl and zlib support.