Support for ignoring white space with git diff

git diff needs option to use --ignore-space-change checkbox (and a few other options would be nice too), and/or a generic setting to set any options for all the git (and other version control) commands that are used by Qt Creator.

Rationale: Qt Creator can do nice code re-indentation and end-of-line white space removal for entire source files. Using this feature on a differently formatted code should not make version controls' diffs next to useless.