Replace all occurrences of [ with [[ in bash and zsh scripts and
configs.
Performance wise it makes sense to use the builtin instead of calling an
external command also when from a functionality stand point `test` would
suffice.
Convert all functions that are pretty much oneliners and do not contain
any real logic into aliases by using anonymous functions.
I am not too sure if I will keep it this way.
Combine functions{Pre,Post}.zsh into functions.zsh. There is no reason
or sense in splitting the functions like that and differentiating
between functions that should be loaded before and after sourcing the
aliases.
Rename the functions from funcPre, making their aliases superfluous.
