Changes for version 0.20
- Moved test for Linux into Build.PL and die with the correct error string so automated things (e.g. CPAN Testers) give up on other platforms.
- Switched license from BSD to Perl.
- Use H2PM to find the correct ioctl numbers at compile time rather than executing hardcoded ones and hoping for the best.
- Use H2PM to get the ext2 flag constants. The ext3/4 constants are still included as the ext3/4 headers don't seem to be available in userland.
- Removed some unused and undocumented things.
Linux ext2/3/4 filesystem attributes.