Merge pull request #293 from arduino/cleanups

Some cleanups to the codebase

Merge pull request #286 from arduino/upgrade_libs

Upgraded a lot of libraries

Merge pull request #285 from arduino/disable-cgo

Disable CGO in builds to avoid linking newest GLIBC

Merge pull request #284 from arduino/fix_tmpdir_cleanup

Fix arduino-lint-report temp dir cleanup