Describe the bug
If $EDITOR is not set when common-aliases is initialized, it will result in empty suffix aliases that send zsh into an infinite loop and the process needs to be killed:

$ alias -s
c=''
cc=''
txt=''
...

To Reproduce
Steps to reproduce the behavior, for example:

1. Enable the common-aliases plugin, and do not set $EDITOR before loading ohmyzsh.
2. Run command touch foo.txt; foo.txt (NOTE: you will have to find the PID to kill this process)
3. This will send zsh into an infinite loop using lots of CPU resources, and which persists even after the terminal is killed.

Expected behavior
If $EDITOR (or other similar variables) are not set/empty, common-aliases should not set the related aliases.

Desktop (please complete the following information):

• OS / Distro: [e.g. Ubuntu]
• Latest ohmyzsh update?: Yes
• ZSH Version: 5.1.1
• Terminal emulator: [e.g. gnome-terminal]