Add latitude/longitude conversion Goodie

**What does your instant answer do?**
Converts latitudes and longitudes between degree-minute-second (DMS) and decimal format.

**What problem does your instant answer solve (Why is it better than organic links)?**
The user is looking for a calculation result, not a page of information. 

**What is the data source for your instant answer? (Provide a link if possible)**
N/A

**Why did you choose this data source?**
N/A

**Are there any other alternative (better) data sources?**
N/A

**What are some example queries that trigger this instant answer?**
`71° 10' 3" in decimal`
`convert 1.1123 degrees north to degrees-minutes-seconds`

**Which communities will this instant answer be especially useful for? (gamers, book lovers, etc)**
Geocachers, hikers and orienteers, scientists.

**Is this instant answer connected to a DuckDuckHack [instant answer idea](https://duck.co/ideas)?**
Yup, [this one](https://duck.co/ideas/idea/49/decimal-degrees-in-degree-minute-second)

**Which existing instant answers will this one supercede/overlap with?**
Possibly Conversions and anything to do with trigonometry, but I've tried to filter those out.

**Are you having any problems? Do you need our help with anything?**
There are probably lots of weird edge cases that could break this, so please suggest any ideas for additional test cases!

**\*\*Note:** Please attach a screenshot for new instant answer pull requests, and for pull requests which modify the look/design of existing instant answers.
![image](https://cloud.githubusercontent.com/assets/726198/3441216/dafc24c6-0101-11e4-89a6-690140fa8e77.png)

## Checklist
Please place an 'X' where appropriate.

```
[X] Added metadata and attribution information
[X] Wrote test file and added to t/ directory
[Xish] Verified that instant answer adheres to design guidelines(https://github.com/duckduckgo/duckduckgo-documentation/blob/master/duckduckhack/styleguides/design_styleguide.md)
[X] Tested cross-browser compatability

    Please let us know which browsers/devices you've tested on:
    - Windows 8
        [] Google Chrome   
        [] Firefox         
        [] Opera           
        [] IE 10           

    - Windows 7
        [] Google Chrome   
        [] Firefox         
        [] Opera           
        [] IE 8            
        [] IE 9            
        [] IE 10           

    - Windows XP
        [] IE 7            
        [] IE 8            

    - Mac OSX
        [X] Google Chrome   
        [X] Firefox         
        [] Opera           
        [X] Safari          

    - iOS (iPhone)
        [] Safari Mobile   
        [] Google Chrome   
        [] Opera           

    - iOS (iPad)
        [] Safari Mobile   
        [] Google Chrome   
        [] Opera            

    - Android
        [] Firefox         
        [] Native Browser  
        [] Google Chrome   
        [] Opera
```

@mwmiller My thinking was that just having "*decimal number* + degrees" in the query is probably not sufficient evidence that the user is looking for this type of conversion — for example, we don't want to return anything for `is 39.5 degrees a fever`. I considered adding a guard in the decimal -> DMS handling to require one of the other keywords as additional evidence, but it seemed more efficient to just exclude "degrees" as a trigger. The same problem doesn't apply to minutes/seconds, since a query like `can you roast a pheasant in 15.4 minutes` isn't going to pass the latitude/longitude regex anyway.