Release 1.0

* FEATURE: Flush old entries from channel file.
* FEATURE: Flush old channel states.
* BUG: Channel files corrupted when disk is full.
* FEATURE: Enclosure file length vs. actually downloaded file size checking. 
* BUG/FEATURE: Some fallback solution for identifying MIME type when tag is
  missing from RSS.
* BUG: Refine the parameter semantics. -c and -l are mutually
exclusive. The other options are allowed in any combination.

Release 1.x

* FEATURE: mrss MD5/SHA-1 checking.
* FEATURE: Expansion macros for tagging.
* FEATURE: Tag clearing.
* FEATURE: Download to current directory.
* FEATRUE: On-the-fly RSS checking.
* FEATURE: Logging.
* FEATURE: Some sort of progress bar.
* FEATURE: Threaded downloading and persistent HTTP connections.
