Increase control over multiplexer auto-start

Setting the auto-start 'remote' and 'local' zstyles for the screen and
tmux modules to 'true' automatically starts a session in SSH connections
and in local terminals respectively.

Signed-off-by: Sorin Ionescu <sorin.ionescu@gmail.com>

modules/screen/README.md

@@ -10,9 +10,15 @@ Settings
 
 Starts a GNU Screen session automatically when Zsh is launched.
 
-To enable this feature, add the following line to *zpreztorc*:
+To enable this feature when launching Zsh in a local terminal, add the
+following line to *zpreztorc*:
 
-    zstyle ':prezto:module:screen' auto-start 'yes'
+    zstyle ':prezto:module:screen:auto-start' local 'yes'
+
+To enable this feature when launching Zsh in a SSH connection, add the
+following line to *zpreztorc*:
+
+    zstyle ':prezto:module:screen:auto-start' remote 'yes'
 
 Aliases
 -------
@@ -28,6 +34,7 @@ Authors
 *The authors of this module should be contacted via the [issue tracker][2].*
 
   - [Sorin Ionescu](https://github.com/sorin-ionescu)
+  - [Georges Discry](https://github.com/gdiscry)
 
 [1]: http://www.gnu.org/software/screen/
 [2]: https://github.com/sorin-ionescu/prezto/issues

modules/screen/init.zsh

@@ -3,6 +3,7 @@
 #
 # Authors:
 #   Sorin Ionescu <sorin.ionescu@gmail.com>
+#   Georges Discry <georges@discry.be>
 #
 
 # Return if requirements are not found.
@@ -14,7 +15,10 @@ fi
 # Auto Start
 #
 
-if [[ -z "$STY" ]] && zstyle -t ':prezto:module:screen' auto-start; then
+if [[ -z "$STY" ]] && ( \
+  ( [[ -n "$SSH_TTY" ]] && zstyle -t ':prezto:module:screen:auto-start' remote ) ||
+  ( [[ -z "$SSH_TTY" ]] && zstyle -t ':prezto:module:screen:auto-start' local ) \
+); then
   session="$(
     screen -list 2> /dev/null \
       | sed '1d;$d' \