Reduce MySQL requirement to 5.0.

Closes #251.

Changes

@@ -1,6 +1,8 @@
 Revision history for Perl extension App::Sqitch
 
 0.9994
+     - Reduced minimum required MySQL engine from 5.1.0 to 5.0.0. Thanks to
+       @dgc-wh for testing it (Issue #251).
 
 0.9993  2015-08-17T17:55:26Z
      [Bug Fixes]

README.md

@@ -6,7 +6,7 @@ App/Sqitch version 0.9994
 [![Coverage Status](https://coveralls.io/repos/theory/sqitch/badge.svg)](https://coveralls.io/r/theory/sqitch)
 
 [Sqitch](http://sqitch.org/) is a database change management application. It
-currently supports PostgreSQL 8.4+, SQLite 3.7.11+, MySQL 5.1+, Oracle 10g+,
+currently supports PostgreSQL 8.4+, SQLite 3.7.11+, MySQL 5.0+, Oracle 10g+,
 Firebird 2.0+, and Vertica 6.0+.
 
 What makes it different from your typical

dist/sqitch.spec

@@ -229,7 +229,7 @@ package bundles the Sqitch Oracle support.
 Summary:        Sane database change management for MySQL
 Group:          Development/Libraries
 Requires:       sqitch >= %{version}
-Requires:       mysql >= 5.1.0
+Requires:       mysql >= 5.0.0
 Requires:       perl(DBI)
 Requires:       perl(DBD::mysql) >= 4.018
 Requires:       perl(MySQL::Config)

lib/App/Sqitch/Engine/mysql.pm

@@ -105,7 +105,7 @@ has dbh => (
         # Make sure we support this version.
         my ($dbms, $vnum, $vstr) = $dbh->{mysql_serverinfo} =~ /mariadb/i
             ? ('MariaDB', 50300, '5.3')
-            : ('MySQL',   50100, '5.1.0');
+            : ('MySQL',   50000, '5.0.0');
         hurl mysql => __x(
             'Sqitch requires {rdbms} {want_version} or higher; this is {have_version}',
             rdbms        => $dbms,

t/mysql.t

@@ -379,8 +379,8 @@ my $err = try {
             unless $dbh->{mysql_serverversion} >= 50300;
     }
     else {
-        die "MySQL >= 50100 required; this is $dbh->{mysql_serverversion}\n"
-            unless $dbh->{mysql_serverversion} >= 50100;
+        die "MySQL >= 50000 required; this is $dbh->{mysql_serverversion}\n"
+            unless $dbh->{mysql_serverversion} >= 50000;
     }
 
     $dbh->do('CREATE DATABASE __sqitchtest__');