Refactored field names

lib/SugarTrail/Template/Master.pm

             if ($accept || scalar @{$slave_step->{warnings}});
     }
 
-    $slave->{meta}->{'Stm'} = $self->{source};
-    $slave->{meta}->{'Stm Revision'} = $self->get_current_revision();
+    $slave->{meta}->{'Master'} = $self->{source};
+    $slave->{meta}->{'Master Revision'} = $self->get_current_revision();
     $slave->{meta}->{'Params'} = mkmymime($args);
 
     $slave->{steps} = \@slave_steps;

notes/arch.md

         +---------------------------------------+
         | ::Slave # Slave template              |
         +---------------------------------------+
-        | Stm: /release/rc.stm                  |
-        | Stm Revision: 123                     |
+        | Master: /release/rc.stm               |
+        | Master Revision: 123                  |
         | Params: os=7; proto=imap              |
         |                                       |
         | Here the body starts...               |

notes/matrices.md

 
 The above can result in two Slaves:
 
-    Stm: /release/rc.stm
-    Stm Revision: 123
+    Master: /release/rc.stm
+    Master Revision: 123
     Params: arch=amd64
     
     # Parallel showcase #
     5. Restart
 
 
-    Stm: /release/rc.stm
-    Stm Revision: 123
+    Master: /release/rc.stm
+    Master Revision: 123
     Params: arch=x86
     
     # Parallel showcase #
 
 Or one "double" Slave -- notice `Params:` header:
 
-    Stm: /release/rc.stm
-    Stm Revision: 123
+    Master: /release/rc.stm
+    Master Revision: 123
     Params: arch=x86+amd64
     
     # Parallel showcase #