Also I wondered how to increase the number of app symbols in a row in the Trebuchet (CM11s standard-launcher) app drawer.
Then I found the solution:
Install Xposed and the App Settings module. Don't forget to activate both and restart the phone.
In App Settings you can change the DPI for individual apps. E.g. I changed the DPI to 400 for Trebuchet. Now I get 5 apps in a row in the app drawer instead of 4. Same with the Email-app: Now it shows more items in the list of mails, just a little smaller.
Hope this helps.