#120 refactored after comments. Introduced templates. Renamed methods.
#120 first attempt on ConversionMethods, to follow: XMLGregorianCalendar 
Conflicts:
	processor/src/main/java/org/mapstruct/ap/model/BeanMappingMethod.java
	processor/src/main/java/org/mapstruct/ap/model/MapMappingMethod.java
	processor/src/main/java/org/mapstruct/ap/model/Mapper.java
	processor/src/main/java/org/mapstruct/ap/model/MethodReference.java
	processor/src/main/java/org/mapstruct/ap/processor/MapperCreationProcessor.java
	processor/src/main/resources/org.mapstruct.ap.model.Mapper.ftl
#120 refactored after comments. Introduced templates. Renamed methods.