Revert "Revert "Rewrite code updating navigation.rb""

This reverts commit 8866b64e6b40fe917c5ac98b48415f96020f6461.
Update pebbles/cloudera-build to use dell_bios instead of bios.
install-chef-suse: Stop removing redhat_install/ubuntu_install

This is not in the crowbar json template anymore, so no need to make
them empty in crowbar.json.
install-chef-suse: Use network config from /etc/crowbar/network.json

If /etc/crowbar/network.json exists, then we want to use this as the
network configuration (with deep merge).
json-edit: Add ability to remove attributes
json-edit: Spacing fixes
json-edit: Fix setting/removing of some non-existing subattributes

If there's already an attribute like foo.bar set to "test", then it was
failing when trying to do something on the foo.bar.foo attribute.

Now, when setting, we overwrite foo.bar to be a hash, and when removing
we just exit early.
install-chef-suse: Make script idempotent wrt /etc/resolv.conf

Since crowbar overwrites /etc/resolv.conf, we need to keep a copy of it
on the first run of the script to be able to get the original data on
later runs.
install-chef-suse: Move commands around

Perform some cleanup and creation of json files a bit later on, as this
is clearly not needed yet when installing barclamps.
install-chef-suse: Install crowbar barclamp like the other barclamps

It's the exact same command, so just use the same code path.
install-chef-suse: Remove duplicate check for running in screen
install-chef-suse: Move line around, where it makes more sense
install-chef-suse: Add a summary line when installation is complete

This is just nicer in the output.
install-chef-suse: Also call bc-network-admin-helper.rb on network.json

When we have network.json in /etc/crowbar, we also need to validate it.
[Devguide] Formatting tweaks

* Line wrap at 80 characters
* Remove trailing whitespace
* Properly indent HTML table
* Remove bullet for "Before submitting pull requests...", since
  there's only one item
[Devguide] Add links to the community Ruby and Rails style guides
Merge pull request #1878 from jamestyj/master-style-guide

[Devguide] Add links to community Ruby and Rails style guides
Merge pull request #1875 from vuntz/install-chef-suse-tweak

install-chef-suse: Stop removing redhat_install/ubuntu_install
Merge pull request #1877 from vuntz/json-edit-improvements

Several improvements to json-edit tools (for pebbles, suse-only)
Merge pull request #1876 from vuntz/install-chef-suse-network

install-chef-suse: Use network config from /etc/crowbar/network.json