Create function to customize the split-window-below defaults

References:
* http://stackoverflow.com/q/19299438/141220
* http://stackoverflow.com/q/22132877/141220
* http://stackoverflow.com/q/6464738/141220
* http://stackoverflow.com/a/5682758/141220
Set another way for indentation to be affected in a mode-unspecific manner
Add restclient package