Linux javascript bindings support

Hi,
I worked on javascript bindings linux support. This patch:
- Adds Linux local-storage support, and adds a new dependency to ```libsqlite3-dev```
- Adds Linux websockets support, and embeds ```libwesockets.a``` (32 and 64 bit) and headers
- Adds Linux spidermonkey 27 support, and embeds ```libjs_static.a``` (32 and 64 bit), from Ricardo Quesada's fork. See [related pull request](https://github.com/ricardoquesada/Spidermonkey/pull/26).
- Adds Linux javascript bindings support.
- Adds Linux test-javascript build
- Adds Linux multi-platform-js template
- Tests Linux js project creation and compilation with Travis CI.
- Finally should fix #3895