Added private boards. 

Fixes issue 6. (Issue 4 & 7 should closed too from previous pull requests.)

createboard view could look a little nicer, but it's fine.

One test is broken, doesn't seem related to my changes though.

[info] + not return a board when removed
[error] x returns the name of the boards
[error]    List(t3, testCodingBoard1, p1, testCodingBoard2, t1) doesn't contain 't2' (CodingBoardsSpec.scala:43)