export supervisord: Improve process numbering

More consistent with Foreman (see #109).

1. Make numbering 1-based instead of 0-based.
2. Include number in program name.

I also moved the append of `num` to `full_name` from the Python code to the template. I think that this is better, because it will allow folks to control whether or not it gets appended using a custom template (which is hopefully coming soon... :smile:) (see issue #88; PR coming soon...)

##### Example:

```
[marca@marca-mac2 export_test]$ honcho export supervisord .
[marca@marca-mac2 export_test]$ cat export_test.conf
[program:export_test-ansvc-1]
command=/bin/sh -c 'bin/ansvc start'
autostart=true
autorestart=true
stopsignal=QUIT
stdout_logfile=/var/log/export_test/ansvc-1.log
stderr_logfile=/var/log/export_test/ansvc-1.error.log
user=marca
directory=/Users/marca/dev/git-repos/honcho/export_test
environment=PORT="5000"

[group:export_test]
programs=export_test-ansvc-1
```

We are getting closer to making honcho's output match foreman.

```
[marca@marca-mac2 export_test]$ ~/dev/git-repos/foreman/bin/foreman export -a export_test supervisord . && mv export_test.conf foreman.conf
[foreman export] writing: export_test.conf
[marca@marca-mac2 export_test]$ honcho export supervisord . && mv export_test.conf honcho.conf
[marca@marca-mac2 export_test]$ diff -u foreman.conf honcho.conf
diff --git a/foreman.conf b/honcho.conf
index 869012e..9371eae 100644
--- a/foreman.conf
+++ b/honcho.conf
@@ -1,11 +1,11 @@
 [program:export_test-ansvc-1]
-command=bin/ansvc start
+command=/bin/sh -c 'bin/ansvc start'
 autostart=true
 autorestart=true
 stopsignal=QUIT
 stdout_logfile=/var/log/export_test/ansvc-1.log
 stderr_logfile=/var/log/export_test/ansvc-1.error.log
-user=export_test
+user=marca
 directory=/Users/marca/dev/git-repos/honcho/export_test
 environment=PORT="5000"
```

The `command` discrepancy is handled by PR #110.
The `user` discrepancy is handled by PR #111.
Then we will have handled all of the differences mentioned in issue #109.