TODO

* add support for tarball download
  - 1. download tarball if no directory exists or --tarball 
    2. decompress and create .httpup-current
    3. download REPO
    4. sync as usual
  - make sure we create a .httpup-current to ensure all files downloaded are
    md5sum checked or removed

* Think about permission preservation


* man page
- httpup.conf

* Feature:
- add a -k (keep) feature
- better return for findDiff()
- don0t create dir if no matches

* Concept:
change it to use the following syntax:
httpup diff [target dir] - show changed/added/removed files

if baseurl is omitted, it is read from .httpup-urlinfo
if target dir is omitted, httpup looks for an .httpup-urlinfo file in the
current working directory. In order to get such a file, use httpup sync -k
(keep).

* Refactoring:
- make more modular (network handler, file handler)
- refactor main


* Bugs
- handle replacement of files with directories (and the other way around)