During the build of WiredTiger, we insert some #include files into wiredtiger.in to generate wiredtiger.h. As a result of the API changes in pluggable filesystems (WT-2552), WiredTiger now needs stdbool.h included in that list.

We have updated our local SConscipt but the same change needs to be made to src/third_party/wiredtiger/SConstruct in MongoDB.