Build, package and publish pre-compiled binary versions for serial port using node-pre-gyp

Add fallback to buil to node-pre-gyp install command, in case remote binary download fails.

Added travis automated binary build, to generate and pubslish the serialport packages.

Publish binaries adding `[publish binary]` to a commit message or by
adding a release tag.

Add travis automated build for x86 32 bit binaries.[publish binary]
Added support for AppVeyor.

1. Created new appveyor.yml configuration file.
2. We are now packaging and publishing windows 32bit version of the
binary.
Update appveyor.yml to also build, package and publish x64 binary.
Merge pull request #319 from hybridgroup/pre-built-binaries

Added Pre built binaries.