A handful of build system fixes:

A handful of build system fixes:

* (test/unit/Makefile.am) libtool was being passed relative paths of
  sources in .cpp, confusing lcov if -b wasn't given.  Fixed.
  Closes bug #102.

* (configure.ac) --enable-coverage now implies --enable-static
  --enable-static-binary --disable-shared.

* (configure.ac) Create top-level config.status for informational and
  re-configuration purposes.

* (configure.ac) Remove -fvisibility=hidden for debug builds.
  Closes bug #104.

* (test/unit/Makefile.am) Build unit tests with -Wall.

* (various unit tests) Fixed trivially-fixable warnings in building
  unit tests.  (Signedness in comparison, unused variables, etc.)

* (Makefile.builds.in) Copy the binary correctly if it is static.
  (It was failing, but only with --enable-static --enable-shared
  --enable-static-binary.)  Closes bug #103.

* (src/parser/Makefile.am) libcvc4parser.so now links with libcvc4.so.

* Other minor cleanups to the build system.