QUERY, QUERY_STATEMENT, Blocking command & Replication

This is the first version to provide also the PRO packages.

This github release will not include executables that can be downloaded
from plasso1

This version comes with several improvements.

The API is still backwards compatible but we added two new commands:
REDISQL.QUERY and REDISQL.QUERY_STATEMENT

These commands behave exactly like REDISQL.EXEC and
REDISQL.EXEC_STATEMENT, but they accept readonly statements. A statement
that modifies the data is rejected by these new commands.

This allows us to mark those commands as readonly and to use them against
replicas/slave.

The PRO version includes:

• blocking commands, just add the suffix .NOW
• replication, allow AOF and master/slaves (cluster) support.

Also, several improvements to the internals have been made, and now the
code is cleaner and more maintainable.