Remove ctrl-M's at ends of lines in mmgr.cpp and mmgr.h
Give sensible message when all scons options are the default
fix a bug in making an image from one of a different dtype
Clean up the docs in base.py.  Should be part of #511, but commit to master to help keep github from getting overloaded.
Merge branch 'master' into #511

Conflicts:
	galsim/base.py
One more parameter order change to undo.
(#511)