[3080] Fixed link flags for Kea postgresSQL backend build

Changed the definition of PGSQL_LIBS for building Kea with PostgreSQL
backend to use pg_config value for LIBDIR rather than LDFLAGS.  The latter
did not build with PostgreSQL 9.3.4 on OS-X or Centos.

Added OS-X version numbers 10.9.1 and 10.9.2 to the test for setting the value
of bind10_undefined_pthread_behavior.  Without this the death test for
conditional variables fails as the problem introduced in 10.9 is still there
as of 10.9.2.  This is unrelated to PostgreSQL.
[3080] Fix build and unit test errors

Initial review and testing revealed build issues, unit test failures,
and memory leaks.  With these changes it should build and pass unit testing.
There are still runtime issues to address.

Changed expire column type in lease tables to be "TIMESTAMP WITH TIME ZONE",
and added methods to convert to and from such fields to LeaseExchange. This
corrects mismatched time conversion to and from database which was causing unit tests to fail.

Added constructors to PgSqlParam to eliminate use of ".value" initializers and
to provide a safe, uniform way to create parameters for binary data. Prior to
this valgrind was reporting invalid reads when vectors were statically cast
to char*.

Removed superflous BOOST_STATIC_ASSERT and corrected values tested in remaining
check.

Removed use of "SET AUTOCOMMIT TO" as it is no longer supported in PostgreSQL.

Altered failure logic in PgSqlLeaseMgr::openDatabase() to release connection
if it is not NULL. This was causing memory leak in unit tests.

Added PQfinish call to createSchema() function to release the connection to fix
memory leaks during unit testing.

Cleaned most cppcheck complaints.
[3080] Use the correct header name schema_mysql_copy.h in MySQL unit test.
[3080] Replaced use of CURSORs with single step selects

    Changed the SQL statements used to retrieve data to be simple selects
    rather than declared as cursors.  This allows the selects to be executed
    with a single statemen execution, eliminating the need for BEGIN and END
    blocks.

    Other minor clean up.
[3080] Updated bind10-guide, corrected minor logging issues

The procedure for configuring Postgresql backend in bind10-guide
was updated such that database tables are created and thus owned
by the Kea user rather than the postgres user.

Cleaned up some logging issues and minor cosmetics.
[3080] Fixed a couple of typos and errors in doxygen.
[3080] A few additional minor review corrections.

PgSqlLeaseMgr::openDatabase now sets conn_ to NULL after calling PQfinish.
PgSqlLeaseMgr constructor, moved member inits to the initializer list
Fixed exception text.