experimenting with Atom-Shell

- investigating the feasibility of swapping out node-webkit for atom-shell
experimenting with Atom-Shell

- converting more tests away from sinon
finished converting tests away from sinon
converted BaseController module style from simplified commonjs to standard requirejs (r.js compatibility #12)
converted MainController module style from simplified commonjs to standard requirejs (r.js compatibility #12)
converted DirectoryContents module style from simplified commonjs to standard requirejs (r.js compatibility #12)
converted NetServices, ServerList module style from simplified commonjs to standard requirejs (r.js compatibility #12)
fixed DirectoryBreadcrumbs renaming issue (r.js compatibility #12)
converted Directory model module style from simplified commonjs to standard requirejs (r.js compatibility #12)
fixed DirectoryBreadcrumb model renaming issue (r.js compatibility #12)
converted DirectoryExplorer module style from simplified commonjs to standard requirejs (r.js compatibility #12)
converted PlatformInfo module style from simplified commonjs to standard requirejs (r.js compatibility #12)
converted Server module style from simplified commonjs to standard requirejs (r.js compatibility #12)
more tweeks to ServerConnection module style (r.js compatibility #12)
converted ServerOverview module style from simplified commonjs to standard requirejs (r.js compatibility #12)
converted Session and User module styles from simplified commonjs to standard requirejs (r.js compatibility #12)
converted Main router module style from simplified commonjs to standard requirejs (r.js compatibility #12)
converted Base router module style from simplified commonjs to standard requirejs (r.js compatibility #12)
converted App module style from simplified commonjs to standard requirejs (r.js compatibility #12)
switched Boot require.js config from require_browser to requirejs (r.js compatibility #12)