InnoDB warnings in MariaDB

Turn off persistent stats in inno db engine - killing unnecessary warnings

Maintenance

Better processing of mysql.cfg file (allowing for customization) and some Linux file permissions adjustments.

MariaDB and Ubuntu build

1. Dropped support for old MyHomeLib inpx format (1.x)
2. Next (5.7.18) release of MySQL fix (Bug #25611609) introduces dependency on Microsoft Visual C++ 2013 run-time and declares embedded server library (libmysqld) deprecation as of MySQL 5.7.19 and will be removed in MySQL 8.0. So we are switching to MariaDB 10.1.24.
3. Build moved to Ubuntu (Arch is flying too fast for a lot of people - glibc 2.25 is a bit too soon). Additional benefit - now Posix thread library is not required on Windows.
4. On Linux program would attempt to pick up MySQL language files from wrong place when output directory is specified - fixed.

Changes in libruseq database structure

1. Maintenance: gcc 7.1.1, boost 1.64 and go 1.8.3 on all platforms
2. New supported database format: "2017-05-31" - librusec innovating again. For MyHomeLib output formats presently there is no difference between "2011-11-06" and "2017-05-31", however for "ruks" output format additional field will be present in inpx, containing "ReplacedBy" value.

Maintenance

Unifying builds for various platforms in the single script and moving everything to Linux. Builds could now be made on msys2/mingw (windows), Arch (everything) and WSL (everything). Old msys2/mingw build will be retired in the near future.

librusec incompatibilities

1. Fixed bug introduced by previous changes for flibusta
2. Make sure, that sequence number is always integer (ignoring librusec decimal "enhancement")

Maintenance

go 1.8.1
Fixed small bug in libmerge error reporting
Scripts changed a bit for slow flibusta pipes.

Expanding sequence processing

Added "--prefer-fb2=complement". If database info does not have sequence for a book try to read it from fb2 in archive.

Added some processing of "--sequence" for old librusec and current flibusta database format. Order available sequence records by requested type and sort them by level before selecting first non-empty record (Issue #5)

Adding support for libruks

Added new inpx format (output) "--inpx-format=ruks". Resulting inpx will contain one extra field (md5 from database - if avaialble, issue #3 )

Starting from 03/17/2017 flibusta stopped exporting lib.libavtoraliase.sql.gz - handle this gracefully (with warning) rather than fail. It is quite possible that this table does not have useful information anymore (result comparison for fb2 books shows only 2 meaningful differences).

Fixes for librusec

Starting sometime in February librusec books could have non-initialized keywords field in the database (issue #2) - ignore it.