* fix sparse file creation on Alpine linux
* re-enable tests for Alpine
* remove `conv=sparse` flag (rely only on `seek=fullsize` & `count=0`)
* doc: add a reference to busybox's dd
* doc: remove restrictions for OpenBSD, Solaris & AIX (should work as
for Alpine linux now)
* add a changelog fragment
* fix typo
Co-authored-by: Felix Fontein <felix@fontein.de>
Co-authored-by: Felix Fontein <felix@fontein.de>
