Bugfix when header content contains ":"

When a header looks like:
```
content-type: foo:bar
```
It would be read as ```content-type=> foo```. This minor fix make sure that the header will be read as ```content-type=> foo:bar```.

This PR is also a fix for the dispatch_path. The dispatch_path can not contain symlinks or "..". 
I renamed this to $headers to be more clear about the contents of the array