issue fixed: RavenDB-2163
used NProgress prgress bar and spinner to "inform" user about loading (when loading time is between 1sec and 10 sec)
used error message to inform user that waiting time is too long (when reaching 10 sec mark)
Merge branch 'master' of https://github.com/ayende/ravendb into RavenDB-2163
Minor
Merge branch 'RavenDB_2282' of https://github.com/maximburyak/ravendb
1. added progress bar when json loading
2. nprogress styling changed to be much bigger, also, coloring was changed.
3. removed the spinner.
Merge branch 'master' of github.com:ayende/ravendb
Merge branch 'RavenDB-2163' of https://github.com/maximburyak/ravendb

Conflicts:
	Raven.Studio.Html5/Content/app.css