removing typecast that requires inner knowledge of VirtualProxyContentPlugins and prevents wrapping content plugins
changing the tag handler plugin API so make it easier to make the next set of changes to move used bundle logic into content plugins
moving used bundle logic into content plugins so content paths are filtered when plugins (e.g. AppCache) request content paths from another plugin
changing ContentPlugin API to remove the duplicate Prod and Dev methods in favour of RequestMode as a param
changing TagHandlerPlugin API to remove the duplicate Prod and Dev methods in favour of RequestMode as a param
removing duplicate app create bundle request in favor of RequestMode
filtering css resource content paths based on what is used in css files
including css resources referenced via index pages as used content paths
outputting some bundles from cssresource content plugin if they are common image types incase they are referecned from .less or .sass files
Merge branch 'develop' into output-used-bundles-v2

Conflicts:
	brjs-core/src/main/java/org/bladerunnerjs/model/app/building/AppBuilderUtilis.java
	brjs-core/src/main/java/org/bladerunnerjs/plugin/plugins/bundlers/css/CssRewriter.java
	brjs-core/src/main/java/org/bladerunnerjs/utility/AppRequestHandler.java
	brjs-core/src/test/java/org/bladerunnerjs/spec/plugin/bundler/css/CssTagHandlerPluginTest.java
renaming badly named test
preventing IO exception if index.html doesnt exist and we try to list the tags used
Merge branch 'develop' into output-used-bundles-v2

Conflicts:
	brjs-core/src/main/java/org/bladerunnerjs/plugin/plugins/bundlers/unbundledresources/UnbundledResourcesContentPlugin.java
Merge branch 'develop' into output-used-bundles-v2
changing inline plugin so it works with the new plugin interfaces
Update AspectTest.java

correcting typo in test name
Merge pull request #1055 from BladeRunnerJS/output-used-bundles-v2

Output used bundles v2