add swig flags
tuttleHost, OfxhSet: fix operator name
OfxhSet: add an index accessor
travis: allows failures on macos due to time limit
enable TUTTLE_PRODUCTION by default
cmake: add doxygen
doxygen: update doxyfile
cmake: add ofxplugins target

Create an alias for all OFX plugins.
Warp: fix icon filename
tuttleCommon: declare pthread dependency