Fix emails in headers. @mysql.com addresses are no more since many years.

Move free_chunk and resize_chunk into memory pool

Drops 24 bytes from each chunk. For the example in bug #71468 it
reduces memory usage by 30%.

Merge branch 'PHP-7.0'

* PHP-7.0:
Update header to PHP Version 7
Happy new year (Update copyright to 2016)
Happy new year (Update copyright to 2016)

Merge branch 'PHP-5.6' into PHP-7.0

* PHP-5.6:
Happy new year (Update copyright to 2016)

Happy new year (Update copyright to 2016)

Merge branch 'PHP-7.0'

Fixed bug #70949 (SQL Result Sets With NULL Can Cause Fatal Memory Errors)

MNDR:
- less dereferencing in mysqlnd_ps . Dereference stmt->conn only once and
use a stack variable. Also make the source cleaner.

MNDR:
- remove unused macros

MNDR:
- move things out of mysqlnd_priv.h

MNDR:
- move from char* + len to MYSQLND_STRING
- add some more const modifiers

MNDR:
- better name for MYSQLND_PPEC - MYSQLND_PFC (protocol frame codec)

MNDR:
- rename MYSQLND_NET to MYSQLND_PPEC (protocol packet envelope codec).
PPEC does only the encoding and decoding to the protocol frame.

MNDR:
- clean up some things

MNDR:
- now send_command_handle_response() also doesn't depend directly on
MYSQLND_CONN_DATA

MNDR:
- pass connection closer and its context
- remove unused parameter

MNDR:
- rename the macro for updating the connection state

MNDR:
- Remove the SET_STMT_ERROR macro

MNDR:
- make MYSQLND_ERROR_INFO a class

MDNR:
- make MYSQLND_UPSERT_STATUS more like an object that a simple structure
Still use macros to make updates simple

MDNR:
- Refactor the command factory. Let the factory be exchangeable.

MDNR:
- remove dead code

MDNR:
- send_command() is no more, thus we need commands for all COM_STMT_*
+ CHANGE_USER

MNDR:
- don't use the static function name but the hook

MNDR:
- remove static function and make it a method. The function doesn't need to
be in mysqlnd_ps.c as it doesn't use any resources anymore from it (it used
in the past)