1.2

Major rewrite of sysclean using perl(1):

• more accurate control of path walkthough (doesn't explore unknown directories)
• no more manual parsing of PKG_DB files
• manage more accurately @sample directories

Incompatible changes:

• the format of sysclean.ignore as slighlty changed: patterns aren't possible now, but just plain filenames.
• network configuration files (/etc/hostname.*) aren't automatically ignored. You should add them to sysclean.ignore