Activity and settings should be moved into user profile

# Overview

Move all of the activity pages and account settings into the profile view that are visible when viewing your own profile.

## Tab: Activity

URL: /people/X
Same as current profile (/activity is duplicated)
## Tab: Orders

URL: /people/X/orders /people/X/orders/bounties /people/X/orders/pledges
Consolidate /activity/bounties, /activity/pledges, /activity/transactions into this tab.
## Tab: Fundraisers

URL: /people/X/fundraisers
Move from /activity/fundraisers to here. Remove at some point since fundraisers now belong to teams.
## Tab: Bounty Claims

URL: /people/X/claims
Move from /activity/claims to here.
## Tab: Cash Outs

URL: /people/X/cash_outs
Consolidate /activity/cash_outs and /activity/cash_outs/new into this tab.
## Tab: Settings

URL: /people/X/settings /people/X/settings/linked_accounts /people/X/settings/email
Add [stacked pills](http://getbootstrap.com/components/#nav-pills) for "Profile", "Linked Accounts" and "Email".
## Misc
- All /activity routes should be removed.
- Legacy redirects for all old paths to the new ones.
- Clean up up the usernav drop down in header (just one link for "Settings", etc)
##

Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/1808172-activity-and-settings-should-be-moved-into-user-profile?utm_campaign=plugin&utm_content=tracker%2F47&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F47&utm_medium=issues&utm_source=github).