With SPDeployer you can specify via a config file, that you want to upload a file to SharePoint on each save.
More info here: http://mwiede.me/spdeployer
You can find the sources on GitHub here: https://github.com/mwiedemeyer/SPDeployer
Update 1.4.3: Fix for site url
Update 1.4.2: Updated for Visual Studio 2015
Update 1.4: Added a new feature to monitor external files and fixed an issue with "compiled files"
Update 1.3: SPDeployer now supports "compiled files" like you usually have if you are developing in TypeScript. Then the compiled js file should be uploaded.