BApplication::Private class for accessing relevant parts.
* Pulled the app server connection and IK initialization out of
InitData() into a new method _InitGUIContext() and introduced a private
constructor that allows to avoid this initialization. This will be used
for servers that don't have GUI respectively want to init the app server
connection later.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13312 a95241bf-73f2-0310-859d-f6bbb57e9c96