* When building on macos I noticed that libcrypto was not found when using
has_function(). This is because the compiler used to compile the check program
is not being told about the library and include paths. Fix it by passing those
into the has_function() check where appropriate.

* Improve callback performance for non-matching case.

When compiling YARA without Python bindings, stdbool.h is actually used
if it can be used. However Python bindings completely ignore it resulting
in YARA defining its own bool type with sizeof(bool) == sizeof(int).
However before [#1377](https://github.com/VirusTotal/yara/pull/1377), this
can result in different compilation units using different sizes of
bool type and chaos ensues.

* Fix setup.py for *BSD platforms

* Fix setup.py for *BSD platforms (additional)

* Add missing openssl include path.

* Add HAVE_LIBCRYPTO.