Changes since 1.5.0:
- improve/fix cmdline handling
- tell the actual watchdog device specified with -w
- tolerate and strip any leading spaces of commandline option values
- Sanitize numeric arguments
- if start-delay enabled, not explicitly given and msgwait can't be
read from disk (diskless) use 2 * watchdog-timeout
- avoid using deprecated valloc for disk-io-buffers
- avoid frequent alloc/free of aligned buffers to prevent fragmentation
- fix memory-leak in one-time-allocations of sector-buffers
- fix AIO-API usage: properly destroy io-context
- improve/fix build environment
- validate configure options for paths
- remove unneeded complexity of configure.ac hierarchy
- correctly derive package version from git (regression since 1.5.0)
- make runstatedir configurable and derive from distribution
