Gem List Helper

Add helper function to list gems in a pretty way (only with rvm, for now). Add
missng EOF newline and a todo to the ruby plugin.

plugins/ruby/ruby.plugin.zsh

@@ -1,4 +1,6 @@
+# TODO: Make this compatible with rvm.
+#       Run sudo gem on the system ruby, not the active ruby.
 alias sgem='sudo gem'
 
 # Find ruby file
-alias rfind='find . -name *.rb | xargs grep -n'
+alias rfind='find . -name *.rb | xargs grep -n'