Make the text part of an input-group a bit wider and other padding/margin
tweaking.

Conflicts:
	locale/en/LC_MESSAGES/converse.po

Note for debian & ubuntu users

- Added a stamp file for bundler.
- We now specify binary paths for bundler and Sass.
- Added a step "watch" to watch the Sass files.
- Add map file for Sass/CSS

Made some modifications to the code contributed by @thierrytiti and documented
the change.

Fixes #344

Also updated the changelog with #377

Conflicts:
	dev.html

Issue #370 registration fails

Support to send the registration form as legacy or xform, we
use the same variable form_type that was already being used when
calling render
Added submission tests

Two tests were created to see if RegisterPanel.form_type is set
to correctly to legacy or xform when receiving server registration
form.

Fix collapsed group visibility on reload

Close #374

Fixes #372