BUILD: Support libedit readline wrapper

This is used in Mac OS X. Thanks to waltervn for pointing this out and
testing.
FULLPIPE: Plug scene21 in
FULLPIPE: Implement sceneHandler21()
FULLPIPE: Implement sceneHandler21_doWiggle()
FULLPIPE: Rename vars in scene21
FULLPIPE: Implement scene21_updateCursor()
FULLPIPE: Enable scene21. This completes the scene
FULLPIPE: Initial code for scene31
FULLPIPE: Plug scene31 in
FULLPIPE: Implement sceneHandler31()
FULLPIPE: Implement sceneHandler31_testCactus()
FULLPIPE: Rename vars in scene31
FULLPIPE: Enable scene31. This completes the scene
FULLPIPE: Initial code for scene30
FULLPIPE: Plug scene30 in
FULLPIPE: Implement scene30_enablePass()
FULLPIPE: Implement scene30_updateCursor()
FULLPIPE: Implement sceneHandler30()
FULLPIPE: Rename vars in scene30
FULLPIPE: Enable scene30. This completes the scene