Fix warnings
Use latest parent pom
add licence-header.txt
Improve the way to assert exceptions Fixes #255
Update licence in classes javadoc
Merge remote-tracking branch 'local/master' into java-8

Conflicts:
	pom.xml
	src/test/java/org/assertj/core/error/ShouldHaveAtLeastOneElementOfType_create_Test.java
	src/test/java/org/assertj/core/error/ShouldHaveOnlyElementsOfType_create_Test.java
Lambda exception assertion - Fixes #287