Reformat all code using astyle.
Update all header guards. Don't start with underscores, as those are reserved for system libraries. Make sure all start with TINC_, and that they appear at the top of the file.
Modernize the build system. Recent versions of autoconf and automake were giving a lot of warnings. This is sort of a backport of similar build system changes from the 1.1 banch: - Fix all autoconf/automake warnings. - Merge lib/ into src/. - Don't use symlinks for device.c any more, but use automake conditionals. - Use explicit paths to local header files. - Get rid of alloca.c/malloc.c/memcmp.c/realloc.c.