chrome_resources take 2

Second try of landing chrome_resources project.  Changes from last time:
- fix scons dependencies by adding a target for grit/theme_resources.h
- fix mac build by adding grit to unittest include path
- fix check deps by adding rules for /grit dir.

Create a chrome_resources.vcproj that holds grd files that hold
non-string resources.  Put browser_resources.grd into this vcproj.

Port theme_resources.rc/theme_resources.h to theme_resources.grd
and put it in the vcproj too.

I did a find/replace on the theme_resources include line.

Modify grit so header files go in grit_generated_resources/grit/
so the include path can be cleaner.  I'll migrate the others
in follow up patches.

theme_resources.rc had a conditional include of distribution_resources.rc
so I had to add support for preprocessor defines to visual studio.

[tony, 2009-02-12 17:05:23]

TBR yesterday's change.