[JSP][Thymeleaf] Removed old webapps used in integration tests
[Core] Implemented the DatatablesCriteria.isFiltered() method

Closes #264
[All] Global reorganization and adaptations to the new asset generators

All:

 * Simplified package organization
 * Added Javadoc & comments
 * Cleaned main POM. Added staging configuration for UML generation in Javadoc

Core:

 * Removed the InsertMode enum and now use JQueryContentPlaceholder instead
 * JavascriptFunction and JavascriptSnippet moved (and renamed) to dandelion-core
 * Removed the useless ConfigurationLoader interface and corresponding extension point based on the "dandelion.datatables.confloader.class" system property. StandardConfigurationLoader renamed to ConfigLoader
 * All i18n-related classes moved to dandelion-core
 * Removed unused utilities such as ClassUtils and FileUtils

JSP:

 * insert attribute of the ExtraJs tag renamed to placeholder

Thymeleaf:

 * dt:insert attribute renamed to dt:placeholder
[Core] Added new debug menu and pages

* One for the options currently enabled in a page. All options are sorted by option group
* One for the DataTable's debugger (pending)
[Core] Processing message is enabled is now enabled by default
[Core] Adapted the bundle loader accordingly with dandelion-core
[Core] To 1.10.x: reloading is supported by default

Linked with #241
[Core] 0.10.x: refactored all AJAX-related features

Linked with #241
[Core] 0.10.x: updated datatables and jquery bundles

Linked with #241
[Core] 0.10.x: adapted main config generator

Linked with #241