Added/modified some useful aliases.

I added `-h` to these aliases. That shows up humanized filesizes.

``` bash
 alias lsa='ls -lah'
 alias l='ls -lah'
 alias ll='ls -lh'
 alias la='ls -lAh'
```

To prevent headaches I added the verbose flag to `cp`, `mv` and `rm`. The output may look like this.
```
$ touch file
$ cp file file1
„file“ -> „file1“
```