Improve admin area button style

A lot of the buttons in the top right in the admin area were too big. This makes those the new `btn-nr` size which seems to look nice.

## User buttons

### Current

![Screen_Shot_2016-01-08_at_2.29.30_PM](/uploads/8920d4a67ff4a20617e5b4d319ba154e/Screen_Shot_2016-01-08_at_2.29.30_PM.png)

### New

![Screen_Shot_2016-01-08_at_2.29.21_PM](/uploads/494741f6e92592ff2c60683f399bb1c1/Screen_Shot_2016-01-08_at_2.29.21_PM.png)

## Project edit button

### Current

![Screen_Shot_2016-01-08_at_2.29.59_PM](/uploads/09a2f8fddc45120510dd10758ce33c51/Screen_Shot_2016-01-08_at_2.29.59_PM.png)

### New ![Screen_Shot_2016-01-08_at_2.30.14_PM](/uploads/93a72a7c42b1974643b1e9ffd3ec8511/Screen_Shot_2016-01-08_at_2.30.14_PM.png)

## Label button

### Current

![Screen_Shot_2016-01-08_at_2.38.09_PM](/uploads/9cff790e1a4e2d650487c9765d0235a4/Screen_Shot_2016-01-08_at_2.38.09_PM.png)

### New

![Screen_Shot_2016-01-08_at_2.38.31_PM](/uploads/9462ff2393249eb762dc7cb92605c733/Screen_Shot_2016-01-08_at_2.38.31_PM.png)

cc/ @jschatz1 @creamzy @skyruler 

See merge request !2351