Also fixed special accounts initialization and special_accounts_tests.

Moved special_accounts_tests and wallet_tests into unittests.

Don't set the cmake variable OPENSSL_LIBRARIES. It's very clear from the documentation that that's an output variable. Not an input variable.

This resolves a benign but worrisome warning from cmake on chainbase_test.

cmake requires that cmake_minimum_required() occurs first thing in the cmake file. Yes, even before project()! Not doing this leads to some spooky things, one of which was the need for us to manually stuff -std=c++14 in to the build flags for macOS. Fix that issue; bump cmake requirement to 3.5 since it is the minimum we've tested with; and make it clear all platforms will use gnu++14 for now.

use gnu++14, part of our use of BOOST required extended numeric literals.  The resolution was "-std=gnu++11 or -fext-numeric-literals"

Capture required cmake commandline in build script.

This module is no help at all for resolving /usr vs /usr/local prefixes.
${CMAKE_INSTALL_BINDIR} is simply the string literal 'bin'.  No magic.
No help.  ${CMAKE_INSTALL_FULL_BINDIR} is '/usr/local/bin' which is
the wrong path for a prebuilt binary.  /usr/local is still unsupportable
as long as CPack is defective by design.  (Or until Debian and
derivatives adopt the FreeBSD convention of putting absolutely
everything into /usr/local, including etc, and eradicating the
distinction between packaged and locally built binaries.)

Be proper UNIX citizens in expected directory hierarchy.

Support independent data and config directories in eosiod.
Start successfully on first launch whether installed or just built.
Honor EOSIO_ROOT environment variable in eosiod.
Regularize whitespace in eosiod main.cpp.
Remove cruft and fix typo in top level CMakeLists.txt.
Add support for CMake v3.6 packaging features, and emulate in older
versions.
Update skeleton contract if it changes, and install it in an eosio
directory.
Add an eosio user and group in .deb package and set appropriate
permissions.
Regularize whitespace in various CMakeLists.txt.
Add libmongoc dependency to Debian package if built with mongo support.
Add self-registration to template plugin.
Remove last reference to steemd in CMakeLists.txt.

Support independent data and config directories in eosiod.
Start successfully on first launch whether installed or just built.
Honor EOSIO_ROOT environment variable in eosiod.
Regularize whitespace in eosiod main.cpp.
Remove cruft and fix typo in top level CMakeLists.txt.
Add support for CMake v3.6 packaging features, and emulate in older
versions.
Update skeleton contract if it changes, and install it in an eosio
directory.
Add an eosio user and group in .deb package and set appropriate
permissions.
Regularize whitespace in various CMakeLists.txt.
Add libmongoc dependency to Debian package if built with mongo support.
Add self-registration to template plugin.
Remove last reference to steemd in CMakeLists.txt.

* Don’t accept system clang & friends. This leads to a lot of confusion.
* Remove a few remaining cmake conditionals checking if WASM compiler is present or not. It always has to be present now.