Bug 3759: OpenSSL compilation error on stock Fedora17, RHEL, CentOS 6 systems

Bug 3759: OpenSSL compilation error on stock Fedora17, RHEL, CentOS 6 systems

OpenSSL-1.0.x has changes in TXT_DB interface over the earlier openSSL releases.
Also looks that the IMPLEMENT_LHASH_* macros are not correctly implemented and
causes compile failures.
Some of the linux distributions to overcome the above problems trying to patch
openSSL SDK. For squid this is means that the current checks based on openSSL
version can not work.

This patch try to detect at configure time:
 - if the TXT_DB uses the new implementation investigated in openSSL-1.0.x
   releases
 - If the IMPLEMENT_LHASH_* openSSL  macros are correctly implemented.

Then uses the autoconf defines to implement the correct workarounds for used
openSSL SDK.

This is a Measurement Factory project