[dev-db/mysql] added last 5.7 for short-term usage (hopefully)

test suite not run yet, but builds and works

dev-db/mysql/files/my.cnf-5.7

@@ -0,0 +1,3 @@
+# @GENTOO_PORTAGE_EPREFIX@/etc/mysql/my.cnf: The global mysql configuration file.
+
+!includedir @GENTOO_PORTAGE_EPREFIX@/etc/mysql/mysql.d

dev-db/mysql/files/my.cnf.distro-client

@@ -0,0 +1,21 @@
+# @GENTOO_PORTAGE_EPREFIX@/etc/mysql/50-distro-client.cnf: The global mysql configuration file.
+
+# The following options will be passed to all MySQL clients
+[client]
+socket						= @GENTOO_PORTAGE_EPREFIX@/var/run/mysqld/mysqld.sock
+character-sets-dir				= @GENTOO_PORTAGE_EPREFIX@/usr/share/mysql/charsets
+loose-default-character-set=utf8
+
+[mysql]
+# uncomment the next directive if you are not familiar with SQL
+#safe-updates
+
+[mysqldump]
+quick
+max_allowed_packet			= 16M
+
+[myisamchk]
+character-sets-dir=@GENTOO_PORTAGE_EPREFIX@/usr/share/mysql/charsets
+
+[myisampack]
+character-sets-dir=@GENTOO_PORTAGE_EPREFIX@/usr/share/mysql/charsets

dev-db/mysql/files/my.cnf.distro-server

@@ -0,0 +1,28 @@
+# @GENTOO_PORTAGE_EPREFIX@/etc/mysql/50-distro-server.cnf: The global mysql configuration file.
+
+# add a section [mysqld-4.1] or [mysqld-5.0] for specific configurations
+[mysqld]
+character-set-server				= utf8
+user						= mysql
+port						= 3306
+socket						= @GENTOO_PORTAGE_EPREFIX@/var/run/mysqld/mysqld.sock
+pid-file					= @GENTOO_PORTAGE_EPREFIX@/var/run/mysqld/mysql.pid
+log-error					= @GENTOO_PORTAGE_EPREFIX@/var/log/mysql/mysqld.err
+basedir						= @GENTOO_PORTAGE_EPREFIX@/usr
+datadir						= @DATADIR@
+skip-external-locking
+lc_messages_dir					= @GENTOO_PORTAGE_EPREFIX@/usr/share/mysql
+#Set this to your desired error message language
+lc_messages					= en_US
+
+# security:
+# using "localhost" in connects uses sockets by default
+# skip-networking
+bind-address					= 127.0.0.1
+
+log-bin
+server-id					= 1
+
+# point the following paths to different dedicated disks
+tmpdir						= @GENTOO_PORTAGE_EPREFIX@/tmp/
+#log-update					= @GENTOO_PORTAGE_EPREFIX@/path-to-dedicated-directory/hostname