Changed code structure to work with Maven, added Maven POM file.
Added gradle build script.
Merge with branch 'maven'

Conflicts:
	src/com/eprosima/idl/parser/tree/Annotation.java
	src/com/eprosima/idl/parser/typecode/Annotation.java
	src/main/java/com/eprosima/idl/parser/tree/Annotation.java