Handle --version option (issue #106).

git-svn-id: http://include-what-you-use.googlecode.com/svn/trunk@526 812d1f90-f944-d88a-411a-122bdc93e1ea
Fix indentation in ParseIwyuCommandlineFlags.  No functional change intended.

git-svn-id: http://include-what-you-use.googlecode.com/svn/trunk@527 812d1f90-f944-d88a-411a-122bdc93e1ea