MVEL-310 Collection access fails when variable type changes (e.g. array->list)

Conflicts:

src/main/java/org/mule/mvel2/optimizers/impl/refl/nodes/ArrayAccessor.ja
va
	src/test/java/org/mule/mvel2/tests/core/PropertyAccessTests.java

Conflicts:

src/main/java/org/mule/mvel2/optimizers/impl/refl/nodes/ArrayAccessor.ja
va
	src/test/java/org/mule/mvel2/tests/core/PropertyAccessTests.java