COMP: Bump JsonCpp to r276.

Add missing istream header for missing getline on Mac Clang build.
Merge pull request #266 from thewtex/jsoncpp-bump

COMP: Bump JsonCpp to r276.
ENH: Now supports building with Boost and Slicer models (boost static)
ENH: Force use of static boost libs
Merge pull request #267 from aylward/BoostSupport

Boost support
ENH: Warnings on MacOSX 10.9
Merge pull request #268 from aylward/VTKWarningSuppression

ENH: Warnings on MacOSX 10.9
BUG: Extra malformed line in initial cache file.
Merge pull request #269 from aylward/InitCMakeCacheType

BUG: Extra malformed line in initial cache file.
BUG: Pass TubeTK_BUILD_SLICER_MODULES to InitCache
Merge pull request #270 from aylward/InitCMake

BUG: Pass TubeTK_BUILD_SLICER_MODULES to InitCache
BUG: Extra malformed line in InitCMakeCache.cmake.in
Merge pull request #271 from aylward/InitCMake

BUG: Extra malformed line in InitCMakeCache.cmake.in