Ignore spacing changes in diff (based on same setting as used to
ignore spacing in git blame).

Task-number: QTCREATORBUG-2526

Fix regression where creator was no longer able to run git if the
PATH was not explicitly set in the configuration.

Task-number: QTCREATORBUG-2478
Reviewed-by: Robert Loehning

Make GitClient::synchronousGit use the process environment.

Windows: Add a setting to fake a 'HOME' environment variable
(%HOMEDRIVE%%HOMEPATH%) to make msysgit look for its SSH-keys
there not only when run from git bash, but also from Qt Creator.
Useful in MinGw-setups, where git must not be in the path.

Task-number: QTCREATORBUG-1577

Do 'git rebase --abort' if something fails.

- Observe timeout setting when running synchronous commands.
- Increase Default on Windows
- Stop process with terminate first (signal).
Task-number: QTCREATORBUG-777

Defaulting to true.

Task-number: QTCREATORBUG-502

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

Make the git plugin look for the binary in the path specified in the settings. Previously, the environment was passed to the process, but that did not affect the location of the binary.

RevBy:    tba
Details:  - as on windows some git commands take much longer it happens fairly often, that git timeouts.
          - added a timeout value to the option to let the user choose maximum timeout value (minimum is 10 seconds, maximum 5 minutes)