add uniform API for annotation access to AnnotationTarget

[Ladicek]

The AnnotationTarget interface gains these methods:

• boolean hasAnnotation(DotName)
• AnnotationInstance annotation(DotName)
• Collection<AnnotationInstance> annotations(DotName)
• Collection<AnnotationInstance> annotationsWithRepeatable(DotName, IndexView)
• Collection<AnnotationInstance> annotations()
• boolean hasDeclaredAnnotation(DotName)
• AnnotationInstance declaredAnnotation(DotName)
• Collection<AnnotationInstance> declaredAnnotationsWithRepeatable(DotName, IndexView)
• Collection<AnnotationInstance> declaredAnnotations()

Many classes that implement AnnotationTarget already had a lot
of these methods. First major change here is that now, all
implementations of AnnotationTarget do. A second major change
is the addition of methods with "declared" in the name: those only
look at annotations present on the annotation target in question
and not on nested annotation targets. Finally, a third major change
is that the collection-returning methods now always return immutable
collections.

The Type class is expanded to provide a similar set of methods:

• boolean hasAnnotation(DotName)
• AnnotationInstance annotation(DotName)
• Collection<AnnotationInstance> annotationsWithRepeatable(DotName, IndexView)
• Collection<AnnotationInstance> annotations()

The MethodParameterInfo class is a first-class citizen now.
It is possible to navigate from MethodInfo to all parameters
represented as MethodParameterInfo, plus MethodParameterInfo
exposes the parameter type. MethodInfo also exposes the number
of parameters directly as parametersCount().

All this happens only on the API level, internal representation
of anything doesn't change. There are two breaking changes:

• the ClassInfo.annotations() method no longer returns a Map,
  it returns a List now; the original method is still available
  as annotationsMap()
• the MethodInfo.parameters() method no longer returns a List<Type>,
  it returns a List<MethodParameterInfo> now; the original method
  is still available as parameterTypes()

Additionally, all the ClassInfo.classAnnotation* methods are
deprecated in favor of declaredAnnotation*.

Resolves #131.