Revert "WIKI-663 create new revision when editing title page inline, show diff between page titles" due to WIKI-746

This reverts commit 0e1a847308006b9e02521e55c6b06a42a64c1f7a.

Conflicts:
	wiki-service/src/main/java/org/exoplatform/wiki/service/WikiService.java
WIKI-746 Slow invocation of PageImpl.checkin for wiki page update - backport to feature/stabilization.

Fix description:
* When a wiki page is modified, a new version will be created only for wiki's content child node instead of the whole wiki page node.
  That allows to improve much the performance.
* Migrate legacy wiki page on the fly, when the user opens the wiki page itself.

Conflicts:
	wiki-renderer/src/main/java/org/exoplatform/wiki/rendering/util/Utils.java
	wiki-service/src/main/resources/conf/portal/cache-configuration.xml
	wiki-service/src/main/resources/conf/portal/wiki-nodetypes.xml
	wiki-upgrade-plugins/src/main/resources/conf/portal/wiki-nodetypes.xml
	wiki-webui/src/main/java/org/exoplatform/wiki/webui/UIWikiPageContentArea.java