Filter build folder resources in eclipse

Apply eclipse project 'filter' to hide generated build artifacts from
the workspace.
Polish AbstractContextLoader Javadoc

Fix unnecessary HTML escaping from {@code} Javadoc.
Test String to char[] conversion

Issue: SPR-9793
Raise exception on missing request parameters

Issue: SPR-10193
Allow TypeDescriptor array construction

Add a static factory method that can be used to create an array
TypeDescriptor with a specific element type. Allows array types
with generic elements to be constructed.

Issue: SPR-9792
Added "awaitTerminationSeconds" property to ThreadPoolTaskExecutor/ThreadPoolTaskScheduler

Issue: SPR-5387
Polishing
Final preparations for 3.2.1
Consider primary attribute with getBean(Class)

Update DefaultListableBeanFactory.getBean(Class<?> beanClass) to
consider the 'primary' attribute of bean definitions. This makes
getBean() behave in the same way as autowiring.

Issue: SPR-7854