Create the Tool creation feature spec.

[skip ci]
Create the User#tools controller action.
Link to User > Tools view from the user profile
Create the initial User > Tools view.
Create the Tool model and migration.
A user has many tools.
Set the inheritance_column on Tool to nil.

The type column is reserved for STI by default. This changed it to nil so that
we can use the type column to set the type of the tool. In the future, it may
make sense to use STI and revert this commit.
Create the Tool factory and update specs to use it
Create the new_tool_path and new view.

This also adds an empty index action for the Tools controller in order for the
form_for(@tool) to work.
Add missing closing > on ICLA Sig new div.
Create the create action for Tools.

Display flash notice upon successful tool creation
Redirect the user to their profile > tools tab after creating a tool.
Update the user tools nav active logic.

[skip ci]
Display Add Tool on prof if current user is user.
Create a simple (read as incomplete) tool partial.
Add comment explaining blank Tools#index action.

[skip ci]
Add no tools profile display locale copy.
Make user tools spec name more intention revealing
Require authentication for tool controller actions

All tool controller actions require authentication except for the index action.
Allow enabling/disabling of Tools in the UI/routes

Only display Tool UI in existing views if the ENV variable TOOLS_ENABLED is set
to true. If it is anything other than true, they will not be displayed. It is
set to true by default.
Merge pull request #589 from opscode/tools_create

Allow users to create Tools