Clarify OutgoingMessage#body validations
Clarify OutgoingMessage#body validations

format_of_body isn't very descriptive, so this commit extracts each
component to separate, descriptive methods

andreicristianpetcu/alaveteli_old,Br3nda/alaveteli,nzherald/alaveteli,Br3nda/alaveteli,andreicristianpetcu/alaveteli_old,nzherald/alaveteli,andreicristianpetcu/alaveteli_old,andreicristianpetcu/alaveteli_old,nzherald/alaveteli,Br3nda/alaveteli,Br3nda/alaveteli,andreicristianpetcu/alaveteli,andreicristianpetcu/alaveteli_old,nzherald/alaveteli,andreicristianpetcu/alaveteli,andreicristianpetcu/alaveteli,andreicristianpetcu/alaveteli,nzherald/alaveteli,Br3nda/alaveteli,andreicristianpetcu/alaveteli