XWIKI-8794: Get rid of Portlet API in oldcore

Conflicts:
	xwiki-platform-core/pom.xml
	xwiki-platform-core/xwiki-platform-containers/xwiki-platform-container-portlet/pom.xml
	xwiki-platform-core/xwiki-platform-gwt/xwiki-platform-gwt-api/src/main/java/com/xpn/xwiki/gwt/api/server/XWikiRequestWrapper.java
	xwiki-platform-core/xwiki-platform-oldcore/pom.xml
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiPortletContext.java
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiPortletRequest.java
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiPortletResponse.java
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiPortletURLFactory.java
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiResponse.java
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiServletRequest.java
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiServletRequestStub.java
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiServletResponse.java
	xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiServletResponseStub.java
	xwiki-platform-core/xwiki-platform-scheduler/xwiki-platform-scheduler-api/src/main/java/com/xpn/xwiki/plugin/scheduler/XWikiServletRequestStub.java
	xwiki-platform-core/xwiki-platform-scheduler/xwiki-platform-scheduler-api/src/main/java/com/xpn/xwiki/plugin/scheduler/XWikiServletResponseStub.java
Revert "XWIKI-8789: Upgrade to Infinispan 5.2.0"

This reverts commit a5882e1f557770696caba84663aa2c08bfb06ffc.