New features:
- Added optional LTO support including -fwhole support on e2k arch: --enable-lto
Bug fixes:
- Fix build on musl, avoid glibc-specific code.
- Do not ignore *-{uid,gid} settings if no CAPABILITIES_SUPPORT.
- Fix potential buffer problems in string and memory operations.
- Fix doxygen issues.
- Fix build using autoconf-2.70.
Other:
- Optimize checks using (un)likely.
- Autogenerate program.h
- Fix various gcc warnings.