Shows all section information.

Instead of hiding a service's settings if it is not marked for
installation, this change shows all information by default,
whether service will be marked for installation or not.

Each service is already organized within tabs, additional hiding
of information serves no real purpose.

This also removes code that disables form elements when a
contradicting service is marked for installation.

For example, previously if HHVM were marked for installation, all
of the PHP service fields would be marked as disabled. This created
a problem as disabled fields are not POSTed on form submit and the
sections would not appear in the YAML config file.
Moves Mailcatcher, Work Queues and Search Servers into new tab "Additional Tools"
Re-adds php-extensions to addExtensionToGroup
Minor visual changes for php extensions
Forces all extensions to submit information.

HTML forms will not submit an input[type=checkbox] if the value
is 0.

This breaks our process of throwing all extensions into a
zip because the puphpet engine doesn't see that any information
was sent for that extension.

When an extension install checkbox is not checked, add a hidden
input field immediately after with value "0". This overrides the
unchecked checkbox. When user checks the checkbox to mark
extension for installation, delete the hidden field. If they
uncheck the checkbox, readd the field.