Set $window var based on currently active window

Previously $window was only set by the new_window() helper when it was
passed a name argument. This caused weird behavior cause if it was
called without a name it would simply attempt to recreate the same
window and fail. That was until @blueyed's fix in 2249cf8.

However, the $window var still wasn't being set correctly, leaving
split_v(), split_h() and other helpers to operate on the wrong
window. This is no longer an issue as $window is always set to the index
of the currently active window at the end of new_window() and
select_window().

lib/layout-helpers.sh

@@ -18,13 +18,11 @@ tmux() {
 #   - $2: (optional) Shell command to execute when window is created.
 #
 new_window() {
-  if [ -n "$1" ]; then
-    window="$1"
-    local winarg=(-n "$window")
-  fi
+  if [ -n "$1" ]; then local winarg=(-n "$1"); fi
   if [ -n "$2" ]; then local command=("$2"); fi
 
   tmuxifier-tmux new-window -t "$session:" "${winarg[@]}" "${command[@]}"
+  window="$(__get_current_window_index)"
   __go_to_window_or_session_path
 }
 
@@ -91,6 +89,7 @@ clock() {
 #
 select_window() {
   tmuxifier-tmux select-window -t "$session:$1"
+  window="$(__get_current_window_index)"
 }
 
 # Select a specific pane in the current window.