Improve manual merge screen to deal with types and location fields

We are currently improving the merge screen:

The PR is now ready for QA: https://github.com/civicrm/civicrm-core/pull/7220

New features/improvements:

• Support for merging 'Website' and 'IM' fields in the merge UI
• Support for location 'types' (eg: phone types, website types, IM providers) in the merge UI
• Remove unsupported OpenID (not in API)
• Show matching data between the contacts, to help decide if they are duplicate records (with colour-coded rows)
• Added the contact's 'last modified' date to the merge screen, to assist with decisions regarding which contact information is most up-to-date
• Ability to hide matching data
• Match up the location entity displayed on the 'main' contact side, to the location and type on the 'other' side (previously just displayed the results in order, regardless of location type)
• Improve titles/labels of location blocks
• Improve description of which action will be performed on a row (add/overwrite/add new)
• Tidy up the way location block data is held and passed around internally
• Fix for CRM-17584
• Fix for CRM-17585
• Translate more strings in JS and template
• Move important warning messages to the top of the screen - rather than stuck only at the bottom

Limitations (not regressions):

• Only supports the 'first' entity of each location and type on the main contact side. Ie: you cannot choose which 'home mobile' to overwrite if the contact has multiple 'home mobile' numbers.

Would appreciate testing and comments!