Config and UX improvements

[weex]

Linked Bitcoin addresses to blockexplerer.com and added a config variable blockexplorer which is of the form https://blockexplorer.com (no trailing slash). Use of this variable assumes /address/ is a valid url to view an address so any site that follows that will work. This is kept generic in case we also start linking to transactions ids at some point.

Linked user names to their profile pages which enables much easier navigation of users and ratings.

Converted the ratings page to a more general profile page and changed route to /profile/

Added a config variable api with valid choices being blockr or blocktrail. If the default blocktrail becomes unavialable, rein config api blockr can be used to switch. This config variable is used when getting unspent outputs to build payment transactions on delivery and acceptance.

Rearranged rating form to put controls displaying job titles and user names first.

[coveralls]

Coverage decreased (-0.01%) to 12.76% when pulling c881f9e on weex:master into b69685c on ReinProject:master.

[coveralls]

Coverage increased (+0.08%) to 12.85% when pulling c986943 on weex:master into b69685c on ReinProject:master.

[coveralls]

Coverage increased (+0.07%) to 12.846% when pulling eee3a61 on weex:master into b69685c on ReinProject:master.