[VS Addin] Add default compiler include paths to visual studio

This allows intelisense to find the NaCl compiler
headers and prevents the red underline on standard
include files.

Still not perfect as it doesn't dectect use of
libc++ vs libstdc++ in PNaCl, but a huge improvement.

I ended up forking the default.props files (previously
these were derived from the x86_64 version at package
create time).

TEST= manual local testing.
BUG= https://code.google.com/p/chromium/issues/detail?id=179121

Review URL: https://codereview.chromium.org/594733002

git-svn-id: https://nativeclient-sdk.googlecode.com/svn/trunk/src@1578 050acbb0-2703-11df-ab0a-9f3f633ae91d
9 files changed