[#1386] Add factories for Dataset and Resources
[#1386] Allow to define auth user when using factories

When creating an instance of the factory, users can provide an 'auth_user'
keyword argument with the name of the user that should perform the action.
If they don't provide the 'auth_user' argument the site user will be used
(this user is a sysadmin). If the action should be performed anonymously
(ie no logged in user), auth_user=None should be provided.

Note that the keyword argument could not be named 'user', as some action
functions use this same parameter.
[#1386] PEP8 fixes
[#1364] Change labelling on homepage search area
Add a block for extension authors to extend
Fix documentation for form.select
Update form.html
Use the full organization dict to display orgs

The package page uses only the bits of the organization dict that is returned
from package_show, this doesn't have the image_display_url and therefore
organization images are not shown anymore. This uses a new helper to get the
full organization dict.
[#1601] Add ports.conf change to instructions
[#1550] Show the file name when uploading a resource

Hiding it is bad makes it hard for the user to check its URL (although it makes
it more difficult for her to change it by mistake).

When you first upload, some browsers have a safety feature to not disclosing
the file's full path to the page so, instead of getting something like:

```
/home/vitor/datasets/unemployment.csv
```

You get:

```
C:\fakepath\unemployment.csv
```

To avoid bothering the user showing this ```fakepath``` stuff, we remove it,
showing just the file name. This only happens when uploading a file. The next
time you edit the resource, we'll have the entire URL, so that'll be shown
instead.
[#1550] Merge the merge and attached states into filled state

They're the same now.
[#1550] Refactor the state machine into a simpler architecture

We just have two states now, so we can simplify stuff.
[#1434] add default_show_group_schema for customizing group show
[#1434] use default_show_group_schema when no other schema given
[#1550] Initialize correctly the status of the image-upload
[#1550] Remove "Remove" button, as we now only use the "X" at the input
[#1641] resource_create validates being passed an "url" parameter
[#1641] Recreate resource_create tests as "new_tests"
Minor English typos fixes
Merge branch 'master' into 1386-improve-factories

Conflicts:
	ckan/new_tests/factories.py