Fix decimal handling for MySQLData

This patch was authored by @nostradani and released by @tanner0101.

Improves Foundation.Decimal support on MySQLData (#35).

Fix statement close during binding

This patch was authored and released by @tanner0101.

Fixes an issue causing prepared statements to not close if an error happened during parameter binding (#34).

notes: MySQL NIO will now assert that statements have been closed before the query handler deinitializes.

Fix statement close on error

This patch was authored and released by @tanner0101.

Fixes a bug causing query statements to not be cleaned up (closed) if an error was thrown in the onRow callback (#32, fixes #30).

MySQL driver no longer crashes on auth failures

This patch was authored and released by @gwynne.

• Fix a user-unsolvable crash triggered by any failure whatsoever during the wire protocol handshake.
• Propagate loggers a bit better.

See Git commit log for a detailed explanation of the problem and its solution.

No API changes or additions.

Copy row byte buffer slices

This patch was authored and released by @tanner0101.

Fixes an issue causing MySQLRow to retain large amounts of memory (#28).

Note: Adds an explicit copy to MySQLRow value byte buffer slices allowing wire protocol buffers to be released from memory.

Rmann/fix constraint error

This patch was authored by @JetForMe and released by @gwynne.

The MySQL support wasn't properly detecting duplicate key constraint violations. This change adds MySQLError.duplicateEntry() and associated unit test. A separate PR fixes the constraint test in fluent-mysql-driver.

Decode string from tiny, medium and long blob

This patch was authored by @florianreinhart and released by @tanner0101.

Adds support for .tinyBlob, .mediumBlob, and .longBlob to MySQLData.string (#26, fixes vapor/mysql-kit#275).

Date and Bool fixes

This patch was authored and released by @tanner0101.

• Adds support for converting Foundation.Date to/from MySQL DATE column type (#25).
• Swift.Bool now serializes as TINYINT by default (#25).

Implement length encoding

This patch was authored and released by @tanner0101.

Add support for encoding dynamically sized values longer than 251 bytes (fixes #23).

Support MYSQL_TYPE_NEWDECIMAL

This patch was authored by @thecheatah and released by @tanner0101.

Adds support for MYSQL_TYPE_NEWDECIMAL conversion on MySQLData (#19, fixes #18).