Move system config file to sqitch directory.

This is so we can later store templates there. Maybe.

lib/App/Sqitch/Command/config.pm

@@ -579,9 +579,9 @@ editor is determined by L<Sqitch/editor>.
   my $file_name = $config->file;
 
 Returns the path to the configuration file to be acted upon. If the context is
-C<system>, then the value returned is C<$(prefix)/etc/sqitch.ini>. If the
-context is C<user>, then the value returned is C<~/.sqitch.config.ini>.
-Otherwise, the default is F<./sqitch.ini>.
+C<system>, then the value returned is C<$(prefix)/etc/sqitch/sqitch.conf>. If
+the context is C<user>, then the value returned is C<~/.sqitch/sqitch.conf>.
+Otherwise, the default is F<./sqitch.conf>.
 
 =head1 See Also
 

lib/App/Sqitch/Config.pm

@@ -19,7 +19,7 @@ has '+confname' => (
 
 sub system_file {
     return $ENV{SQITCH_SYSTEM_CONFIG} || file(
-        $Config{prefix}, 'etc', shift->confname
+        $Config{prefix}, 'etc', 'sqitch', shift->confname
     );
 }
 
@@ -110,7 +110,7 @@ Returns the configuration file base name, which is F<sqitch.conf>.
 
 Returns the path to the system configuration file. The value returned will be
 the contents of the C<$SQITCH_SYSTEM_CONFIG> environment variable, if it's
-defined, or else C<$Config{prefix}/etc/sqitch.conf>.
+defined, or else C<$Config{prefix}/etc/sqitch/sqitch.conf>.
 
 =head3 C<global_file>
 

lib/sqitch-config.pod

@@ -139,11 +139,11 @@ See also L<Files>.
 
 =item C<--system>
 
-For writing options: write to system-wide F<$(prefix)/etc/sqitch.conf> file
-rather than the repository F<./sqitch.conf>.
+For writing options: write to system-wide F<$(prefix)/etc/sqtich/sqitch.conf>
+file rather than the repository F<./sqitch.conf>.
 
-For reading options: read only from system-wideF<$(prefix)/etc/sqitch.conf>
-file rather than from all available files.
+For reading options: read only from system-wide
+F<$(prefix)/etc/sqitch/sqitch.conf> file rather than from all available files.
 
 See also L<Files>.
 
@@ -211,7 +211,7 @@ Local, project-specific configuration file.
 
 User-specific configuration file.
 
-=item C<$(prefix)/etc/sqitch.conf>
+=item C<$(prefix)/etc/sqitch/sqitch.conf>
 
 System-wide configuration file.
 
@@ -233,7 +233,7 @@ C<~/.sqitch/sqitch.conf>.
 =item C<SQITCH_SYSTEM_CONFIG>
 
 Take the system configuration from the given file instead of
-C<$(prefix)/etc/sqitch.conf>.
+C<$(prefix)/etc/sqitch/sqitch.conf>.
 
 =back
 
@@ -320,7 +320,7 @@ sqitch command's behavior. The F<./sqitch.conf> file local to each project is
 used to store the configuration for that project, and
 F<$HOME/.sqitch/sqitch.conf> is used to store a per-user configuration as
 fallback values for the F<./sqitch.conf> file. The file
-F<$(prefix>/etc/sqitch.conf> can be used to store a system-wide default
+F<$(prefix)/etc/sqitch/sqitch.conf> can be used to store a system-wide default
 configuration.
 
 The variables are divided into sections, wherein the fully qualified variable

t/configuration.t

@@ -19,7 +19,7 @@ isa_ok my $config = $CLASS->new, $CLASS, 'New config object';
 is $config->confname, 'sqitch.conf', 'confname should be "sqitch.conf"';
 
 is_deeply $config->global_file, File::Spec->catfile(
-    $Config::Config{prefix}, 'etc', 'sqitch.conf'
+    $Config::Config{prefix}, 'etc', 'sqitch', 'sqitch.conf'
 ), 'Defaulg global file name should be correct';
 
 $ENV{SQITCH_SYSTEM_CONFIG} = 'FOO/BAR';