Create a branch for 1.5

[akiraly]

Upstream wicket 1.5 is now on branch so wicketstuff should follow suit.

[mocleiri]

I have created a core-1.5.x branch where the wicket 1.5.x development can containue and switched ci.wicketstuff.org over to use it.

I have also done a commit on master to make jdk-1.5-parent/pom.xml require java 6 since wicket 6.0 will be compiled with java 6.

master is now tracking 6.0-SNAPSHOT and eventually will be built on ci.wicketstuff.org, there are some compile errors due to API differences but at least some of it should compile.

longer term we need to migrate the projects in the jdk-1.5-parent directory into the jdk-1.6-parent directory.

I also plan on supporting java 7 modules with a jdk-1.7-parent directory eventually so I think we should keep the jdk-1.6-parent folder.

[mocleiri]

migration on master of modules into jdk-1.6-parent is complete and I even added in a jdk-1.7-parent for the future.