Introduce Utils::SynchronousProcess::normalizeNewlines

Replaces \r\n? with \n.

Some console applications (e.g. git-push, git-rebase) use \r alone to
move the cursor to the line's beginning. This should be replaced by \n
rather than just be erased.

Change-Id: I8d614d2b471e59decdbfa7f173ffa7fbdb11759b
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>