Hide export on plot detail page. Fixes #637

It is a little confusing to see export on the plot detail page. You
might expect it to export just the single tree, which is not what
happens.
Markup edits to user page, minor styling
Fixes #642
Fixes #649
Style fields on user page, forms
Merge pull request #653 from mtedeschi/topic/style-user-page

Styling: User profile page, little UI bug fixes
Use 20ft as nearby tree radius
Don't show bullet when there are no nearby trees.

Fixes #569
Merge pull request #612 from ahinz/fix/569/nearby-text

Fix/569/nearby text
Allow html in labels

This is useful, for instance, if you want to put dynamic content
into a label. If we had some sort of eco benefits page you might
want a label like:

```
<span class="currency">$</span> per kWh
```

Then in js one could do:

```
$('.currency').html(new_curreny_value);
```
Allow updating benefit values
Support serializing lazy translated fields
Update copy on 403 page
Fixes #648, Update copy on 403 page
Merge branch 'fix/648/403-page-language-seems-harsh' of github.com:mtedeschi/OTM2 into fix/648/403-page-language-seems-harsh
Merge pull request #633 from ahinz/topic/inline-form-fixes

Topic/inline form fixes
Merge pull request #650 from jwalgran/topic/hide-export-on-plot-detail

Hide export on plot detail page. Fixes #637
Merge pull request #673 from mtedeschi/fix/648/403-page-language-seems-harsh

Fix: 403 page copy update
Don't show the add tree button once the feature becomes disabled