Problem: Too difficult to keep warning headers consistent.
Solution: Reference a variable which holds the warning header string
Problem: No builtin way to valgrind or gdb
Solution: Add 'make memcheck' and 'make debug' to automake
Problem: `make memcheck` gives exit code 0 even on failure
Solution: use `--error-exitcode=1` to fail with nonzero exit status
Problem: `make memcheck` and `make debug` do not trigger rebuild
Solution: add automake dependency on selftest libtool wrapper
Problem: Default ci_build.sh does not include memcheck
Solution: Add make memcheck to ci_build.sh
Problem: Library description in pc.in discards formatting
Solution: Don't mess with formatting of description
Merge pull request #55 from jemc/header_fix

Problem: No builtin way to valgrind or gdb