Ignore *.zwc.old files when compiling functions

These files are generated by `zrecompile`.

Also update the .gitignore file.

Closes #218

.gitignore

@@ -1,3 +1,4 @@
 *.swp
 *.zwc
+*.zwc.old
 custom/

login_init.zsh

@@ -20,7 +20,7 @@
   zrecompile -pq ${ZDOTDIR:-${HOME}}/.zshrc
 
   # zcompile enabled module autoloaded functions
-  zrecompile -pq ${ZIM_HOME}/functions ${ZIM_HOME}/modules/${^zmodules}/functions/^([_.]*|prompt_*_setup|README*|*.zwc)(-.N)
+  zrecompile -pq ${ZIM_HOME}/functions ${ZIM_HOME}/modules/${^zmodules}/functions/^([_.]*|prompt_*_setup|README*|*.zwc|*.zwc.old)(-.N)
 
   # zcompile enabled module init scripts
   for zmodule (${zmodules}); do