Added posibility to override the test-name of a problem so you can implement different alternatives:
  euler(problem1) { ... }
  euler(problem1, Some("better performance alternative")) { ... }
Problem 1,2,4
generalise Problem 4
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/test/scala/org/bescala/projecteuler/problems/Problem002.scala
	src/test/scala/org/bescala/projecteuler/problems/Problem004.scala
readded Problem4 locally
re-added Problem002 locally
Problem003
Problem006
Problem009
Problem010
Problem013
Problem018 and Problem067
Added Scala Documentation to package org.bescala.projecteuler
Merge remote-tracking branch 'upstream/master'