Improve source code readability #443

First of all, I really appretiate your work in the development of this great piece of software. I've moved from yaourt to pacaur recently.

I've been digging in the script source code moved by curiosity. I got some experience in bash scripting but I found difficult to follow the application workflow. I'd like to contribute improving readability of the code if you are interested, this could ease maintenance and future contributions to the script functionality.

Basically, I'd focus on these points:

• Add more verbose comments to the code to clarify each step
• Use some comment banners to divide each section clearly
• Break bash lines to improve readability (limit to 80 char each line)
• Unroll some conditionals to improve readability
• Use some bashisms

I've found a short and interesting bash style guide if you want to take a look.

More references:

• Bash Pitfalls
• Community Bash Style Guide
• Bash Style Guide
• Writting Robust Shell Scripts