Add support and accompanying tests for multiple accept headers.
Merge branch 'master' of https://github.com/gmega/p3-transformer-library

Conflicts:
	src/main/java/eu/fusepool/p3/transformer/HttpRequestEntity.java
	src/main/java/eu/fusepool/p3/transformer/util/AcceptHeader.java
	src/test/java/eu/fusepool/p3/transformer/util/AcceptHeaderTest.java