Add gyp flag disable_xslt
Merge pull request #208 from wang16/mini_xslt

Add gyp flag disable_xslt
Turn of xslt in webkit preferences

The preferences will not work any more if disable_xslt
specified. But leave it unchanged is confusing.
Merge pull request #209 from wang16/mini_xslt

Turn of xslt in webkit preferences
Add gyp flag to disable webp