Improvements to translation-systems and adding Norwegian

## Adding Norwegian
Pretty straight forward. 
Translated in a few stages because more strings had come in while I was working. (API-docs) d02c49af8eba9d29f09f1ee43c43ebe33606cabe

I would do these as individual pull requests, but they kind of cropped up as I was translating and finding things I couldn't. Don't worry though, I have more things I want to fix :wink:

## Translation-changes

### Making links translatable
Links within text were largely not available for translation. I fixed that for the following:

- Email Preferences ca776218e15e4404a78c8aab6123e9bb49516dde
- Public Calendar 559394287477acfbdab38b7d582289b360d40dc1
- Special Page 9d88a192fb2714840c6bc83656868f98490751ff

### Text that was in the locale-file, but not used in templates
- Title on My Suggestions e6e9c59e327ed4a176e5d5cce62d0f76f6f643ab

### Forms
Forms were also largely untranslatable, so I fixed that for the following:

- Email preferences 066c8a398b75a5d6f5d6aa509f196f5daf3217d2
- Gifting a2e86ab7ab9e573bc8d3cff107f2998b0bf81ea0
- Suggesting projects cc6e7d9dd63b897a253d39bef1ce6eba9019aeb4
- Gifting on the dashboard 9648ebeb345afdc46b5b59d144ff7b126d0a71a6

### Random text

- Title for Coderwall 78a709640981ead991c90d540c6ed8580f7f9bdb
- "Badges achieved by" (see "translating javascript" below) kimroen@74605c984248640ad184319420ea8e59a72c937c
- "e.g." (hey, it's in the details) kimroen@08059422136708e2f51286922a85803a0d88acd6 and kimroen@7b2559d241b2d368fa7129180beee2cc9a550d95
- "or" kimroen@d918adef5c3354b299adcf98b5601ad5c9ccd93b
- There was a typo in using "cancel" so it didn't get translated. kimroen@bd3f392d09dedba8ae6438f1ac7f8a2f07734521
- Fixed some typos in the new coderwall-errors kimroen@0da23e758b9df59d7147f48f8a2583fac70d4d58

### Inconsistencies

"Suggest an issue" was translated different to the other links within strings, so I fixed that. kimroen@611366b6871b5d1457a686180d855ca78bfa3f1b

**This was a change to the actual keys** in the translations though, so I also went back and corrected it in all the other translations. kimroen@fb56afd630847855eae4514bb7cdb2a00a009970

## Translating javascript
I made an application helper based on some [suggestions on stack overflow](http://stackoverflow.com/questions/2701749/rails-internationalization-of-javascript-strings). kimroen@ada81e395fb69cc47c65fee9066bf77deebdbe01

This will make translations available in javascript by using e.g. `I18n.user.coderwall.achieved_by`
I have commented these out though, because they currently don't fall back to english for untranslated strings. kimroen@1daca7f8b4b5624cf37dbcdb76f389f43a3268e5

If someone could take a look at that, that would be great.

## Updating other locales
Empty keys in locale-files fall back to english, so I went in and added all the new keys to all existing locales for easier translation of new things. kimroen@37de511c8f40c9b4668bd2f7a655a877fd9347c9 (initial) and kimroen@71a56eb3a347b6aeef097e2e5ba96416dbe3b2a5 (API)