faster/better development

[eluser]introvert[/eluser]
Hello,

I want to improve my php codeigniter apps development.

I'd like to improve debugging (using echoes and that seems really retarded) and I want to have a system which could track all the changes in code.

1) debugging
Do you use any special library, technique which can make php development faster and more efficient?
Or you just define function log_me($str) ?

2) code updates
I know about SVN and GIT and i know git is getting more popular and its faster. Which one do you use and why?

Are there any plugins that will detect updated files, highlight them and upload to ftp server?

Any tips for better development are highly appreciated..

Maybe auto backup of the previous version before the new files are uploaded/upgraded as well?
Or any other CI related techniques that will make development easier?

Many thanks for help!