Eliminating some false positives on the Reload plugin

[solsys]

Vim likes to throw .myfile.js.swp files in the same directory as myfile.js. This has the nasty side-effect of forcing Cluster to restart every few keystrokes. This patch just changes the reload filter to only trigger on files with an extension of .js, instead of files that happen to have .js somewhere in the name.

[eirikurn]

This line is changed in my branch to support other file extensions which in the progress fixes this issue. I'll be creating another pull request later today.

[tj]

I'm going to close this, I will fix this extension issue but path.extname() is a bit cleaner