Issuing service stubs
Merge branch 'platypus-fix' of github.com:premium-minds/billy into platypus-fix

Conflicts:
	billy-platypus/src/main/java/com/premiumminds/billy/portugal/BillyPortugal.java
	billy-platypus/src/main/java/com/premiumminds/billy/portugal/services/documents/PTInvoiceIssuingHandler.java