Allow custom/*.zsh configs to override lib/*.zsh files of the same name.

This lets you replace default oh-my-zsh behavior with settings more to your
liking. You can still add on to default oh-my-zsh settings by adding them to
~/.zshrc or directly to the lib/*.zsh files.

oh-my-zsh.sh

@@ -9,9 +9,16 @@ fi
 # add a function path
 fpath=($ZSH/functions $ZSH/completions $fpath)
 
-# Load all of the config files in ~/oh-my-zsh that end in .zsh
-# TIP: Add files you don't want in git to .gitignore
-for config_file ($ZSH/lib/*.zsh) source $config_file
+# Load all library config files in the lib/ folder. If a config file with the
+# same name exists under custom/ load that instead. This allows you to override
+# default behaviors
+for library ($ZSH/lib/*.zsh); do
+  if [ -f $ZSH/custom/$library:t ]; then
+    source $ZSH/custom/$library:t
+  elif [ -f $library ]; then
+    source $library
+  fi
+done
 
 # Set ZSH_CUSTOM to the path where your custom config files
 # and plugins exists, or else we will use the default custom/
@@ -50,9 +57,6 @@ for plugin ($plugins); do
   fi
 done
 
-# Load all of your custom configurations from custom/
-for config_file ($ZSH_CUSTOM/*.zsh(N)) source $config_file
-
 # Load the theme
 if [ "$ZSH_THEME" = "random" ]
 then