Bootstrap3fixes

A bunch of small UI-related changes from #27 (which I'll re-open to keep the menu changes separated):
- reduce the size of the sub-navbar (on the top left)
- remove unused template `form.html`
- update texts of the apps 'users' and 'first_boot'
- again display the help text for first_boot (it was gone, probably unintentionally)
- remove the template-block `js_block`: use `app_js` or `page_js` instead
On Tuesday 25 November 2014 05:37 AM, fonfon wrote:
>> @@ -15,6 +15,12 @@ body {
>>  .sidebar .glyphicon {
>>    margin-right: 4px;
>>  }
>> +.sidebar-nav .nav li a {
>> +  padding: 4px 15px;
>> +}
>> +.sidebar-nav {
>> +  padding-left: 10px;
>> +}
> 
> IMHO the old subnavbar looked cleaner, it was easier to read and find single items. But I don't have a strong opinion here, I'm fine with reverting this change.

We could compare Plinth theme with GitHub.  Notice the veritical pills
styled navbar items is say 'Notifications' page.

Plinth theme does not seem to fully understand clean design of
bootstrap.  It uses dark navigation at the top, it wants to put
everything in grey boxes (a move to flatter interfaces is noticeable
everywhere) etc.  This is reminiscent of older web design style. We
should consider adopting bootstrap design style more closing instead of
simple using it as a library for implementing our own design.  I would
say we experiment with light navbar and removal of wells.

> 
> What do you mean with the vertical bootstrap navbar? Bootstrap doesn't offer any explicit vertical navbar, there are only elements that you could use for that purpose, like we do (linked lists or the 'stacked nav pills' we are using).

I did mean stacked navpills, sorry.  Note that the responsive needs
which are possibly the biggest concern for horizontal navbar just work
out okay with stacked navpills.

> 
> I agree that we should be careful with adapting bootstrap. In this case - imho - it reduces mobile usability but increases readability, so I'm okay with both.
>

Let us give it a try, perhaps we are used to the older one more.  We can
revert later based on how we feel about it and feedback.