Fix for crazy character encoding issue

see http://stackoverflow.com/questions/17682278/msbuild-interprets-file-names-as-chinese-characters-for-some-generated-projects
and http://connect.microsoft.com/VisualStudio/feedback/details/774527

Turns out newlines in 'AdditionalOptions' tag cause serious encoding issues.

WTF, Microsoft?
Merge branch 'improve_scons_a' of github.com:makerbot/mw-scons-tools into improve_scons_a