This removes the all hard dependencies to and from welcome screen,
except the one to the core plugin. More in detail:

- Add IWelcomePage to add a tab to the welcome screen
- Move tabs in the modules where they belong
- Enables QHelpManager to open help fullscreen and contextually
- "Getting Started" moves to Qt4ProjectManager
- Projects & Sessions (aka "Develop") moves to ProjectExplorer
- "Community" remains in the welcome plugin for simplicity

Move WelcomeModeTreeWidget to utils, add d-ptr.

Reviewed-by: Daniel Molkentin

Scroll areas were added to the welcome mode and the project mode, to
make sure they don't limit how small Qt Creator can be made.

Done with mae

Reviewed-by: Trust Me

Conflicts:

	src/libs/cplusplus/CppBindings.cpp
	src/libs/cplusplus/CppBindings.h
	src/libs/cplusplus/FastPreprocessor.cpp
	src/libs/cplusplus/FastPreprocessor.h
	src/plugins/cpptools/cppcurrentdocumentfilter.cpp
	src/plugins/cpptools/cppcurrentdocumentfilter.h
	src/plugins/cpptools/cppsemanticsearch.cpp
	src/plugins/cpptools/cppsemanticsearch.h
	src/plugins/duieditor/parser/qmljs.g
	src/plugins/duieditor/parser/qmljsast.cpp
	src/plugins/duieditor/parser/qmljsast_p.h
	src/plugins/duieditor/parser/qmljsastfwd_p.h
	src/plugins/duieditor/parser/qmljsastvisitor.cpp
	src/plugins/duieditor/parser/qmljsastvisitor_p.h
	src/plugins/duieditor/parser/qmljsengine_p.cpp
	src/plugins/duieditor/parser/qmljsengine_p.h
	src/plugins/duieditor/parser/qmljsgrammar.cpp
	src/plugins/duieditor/parser/qmljsgrammar_p.h
	src/plugins/duieditor/parser/qmljslexer.cpp
	src/plugins/duieditor/parser/qmljslexer_p.h
	src/plugins/duieditor/parser/qmljsmemorypool_p.h
	src/plugins/duieditor/parser/qmljsnodepool_p.h
	src/plugins/duieditor/parser/qmljsparser.cpp
	src/plugins/duieditor/parser/qmljsparser_p.h
	src/plugins/duieditor/parser/qmljsprettypretty.cpp
	src/plugins/duieditor/parser/qmljsprettypretty_p.h
	src/plugins/duieditor/rewriter/rewriter.cpp
	src/plugins/duieditor/rewriter/rewriter_p.h
	src/plugins/duieditor/rewriter/textwriter.cpp
	src/plugins/duieditor/rewriter/textwriter_p.h
	src/shared/cplusplus/ASTClone.cpp
	tests/manual/cplusplus/main.cpp

Reviewed-by: Trust Me

Reviewed-by: Ossi

Reviewed-by: Thorbjorn Lindeijer

Reviewed-By: Thorbjorn Lindeijer

Reviewed-by: dt

Reviewed-by: TrustMe

Reviewed-by: Daniel Molkentin

Reviewed-By: Thorbjorn Lindeijer <thorbjorn.lindeijer@nokia.com>

Reviewed-By: Thorbjorn Lindeijer

It's not the Mac's fault!

Reviewed-By: hjk

When an example is selected, help and the project are opened
in a split view. We try to read the xml file provided for
QtDemo to extract details about the examples provided. Will
try all available Qts, starting with the default version. Will
fail gracefully (provide a message and disable controls) if
examples or demos cannot be found. Will work if help is not
found, but show an error.

Manage Sessions replaces "Restore last session" (which can be done by clicking
the "(last session)" session anyway. Also, added a "Create New Project" button.
Ensured that the welcome screen is only as high as needed (will orient on the
amount of items in the contained treewidgets). Scrolling is still last resort.

Introduce integrated 'Did you know' section, prevent scrollbars.

Reviewed-by: Daniel Molkentin <daniel.molkentin@nokia.com>

This reverts commit f56bdcd5.

... by eliminating images containing text.
of course, this causes some stylistic issues. oh, well.