Add scd plugin for smart change of directory.

Synced with the scd-tracker branch pavoljuhas/oh-my-zsh@9d04d8ca78

plugins/scd/scd.plugin.zsh

@@ -0,0 +1,19 @@
+## The scd script should autoload as a shell function.
+autoload scd
+
+
+## If the scd function exists, define a change-directory-hook function
+## to record visited directories in the scd index.
+if [[ ${+functions[scd]} == 1 ]]; then
+    scd_chpwd_hook() { scd --add $PWD }
+    autoload add-zsh-hook
+    add-zsh-hook chpwd scd_chpwd_hook
+fi
+
+
+## Allow scd usage with unquoted wildcard characters such as "*" or "?".
+alias scd='noglob scd'
+
+
+## Load the directory aliases created by scd if any.
+if [[ -s ~/.scdalias.zsh ]]; then source ~/.scdalias.zsh; fi