Use libtinfo as a fallback for curses

This will be done before running the FindCurses cmake module
Configure travis to perform a 32-bit build

- Build targeting 32-bit with travis
- Code in `before_install`/`after_success` was moved to travis.sh since it
  provides greater flexibility for detecting the build matrix environment. This
  improves the build speed since we now install only what's necessary.
- Now clint has a dedicated travis worker
Fix clint.sh wrapper script and broken files

- Fixed clint.sh, it no longer ignores errors in individual files.
- Fixed two files that weren't passing the clint test