The fake tooltip duplication is not nice.

Broke in f14c50da

Done-with: Roberto Raggi <roberto.raggi@nokia.com>

Yeah, now it looks as bad as the native completion widget :)
Reported by Nigel.

forwarding keys with empty text() does not restrict the matching items, but
updating the list of possible completions resets the currently selected item to
the first one

- this is compatible with choosing completion items in vim
- especially when using FakeVim mode, this makes it unnecessary to move
  the hands from the main row to the arrow keys

Merge-request: 2158
Reviewed-by: hjk <qtc-committer@nokia.com>

It can be a bit disturbing if the list suddenly jumps when you don't
release the down or up key in time.

Done with mae.

Task-number: QTCREATORBUG-199
Reviewed-by: thorbjorn

Reviewed-by: Thorbjorn Lindeijer

There were both variants, with and without extra semicolon.

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

- clear up some Q_OS_LINUX vs. Q_OS_UNIX
- clear up Q_WS_* vs. Q_OS_* (relatively theoretical exercise)
- use proper #if-#else cascades instead of free-standing #ifs

Most desktops allow popups to overlap the taskbar. We should allow this
additional space to be used by the completion popup.

Pop it upwards when it would otherwise go below the screen and shift it
to the left when it would otherwise exit the screen on the right.