Do not clobber environment setting for SSH_ASKPASS.
Pass on QProcessEnvironment to CheckoutWizard.

- Use message boxes on timeouts.
- Add a configuration for a graphical SSH password prompt binary with
defaults
- Launch commands that require authentification with no terminal on UNIX
and environment variable SSH_ASKPASS set accordingly.
- First attempt at introduce a common function to synchronously run VCS
commands in base plugin with flags.
- Use standard execution log entries in all VCS plugins (outputwindow).

To free up the name for an upcoming VCSBaseOptionsPage class that forms
the base for all version control option pages.

Reviewed-by: Friedemann Kleint

Provide a checkable message box to be able to turn
prompting off when asked.

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

Reorganize the settings model in the VCS base plugin, store model in the plugin for better delayed initialization/update.

Fixes: Add common configuration to the VCSA base plugin; submit message check script and user name configuration.                                           Details: Extend submit editor widget by configureable fields. Use them in the VCS base submit editor to specify users, provide completion and selection dialog for them.