Add ResourceTransformer and CSS link implementation

This change adds a ResourceTransformer that can be invoked in a chain
after resource resolution. The CssLinkResourceTransformer modifies a
CSS file being served in order to update its @import and url() links
(e.g. to images or other CSS files) to match the resource resolution
strategy (e.g. adding MD5 content-based hashes).

Issue: SPR-11800
Fix animalSniffer warning
Tweak JmsMessagingTemplateTests for Eclipse 4.4

Eclipse 4.4 early release versions have issues with generics.

This commit slightly tweaks the use of generics in
JmsMessagingTemplateTests so that the class compiles in the latest
builds of Eclipse 4.4