This patch switches code to SPDX one-line license identifiers according to
https://spdx.dev/learn/handling-license-info/
and replacing long license text headers.
I used C++ format on the first line in style
// SPDX-License-Identifier: <id>
except exported libcryptsetup.h, when only C comments are used.
The only additional changes are:
- switch backend utf8.c from LGPL2+ to LGPL2.1+ (as in systemd)
- add some additional formatting lines.
see unit test write_blockwise(length=2097153, bsize=4096), on x86
with original test file size=2097152.
The test is trying to write_blockwise 1 more byte than actual file
size.
Note that both functions perform seek operations aligned to sector
boundary if possible before returning.
Unaligned input offset gets aligned on first preceding sector
boundary.
