2013-11-06-14.58.05: src/lib/prettyprint/big/src/core-prettyprint-mill-g.pkg: For cleaner semantics, changed INDENT and EXDENT to change margin relative to left margin of box rather than relative to current left margin. Now the only difference between INDENT and EXDENT is that EXDENT forces a newline when wrapped.  src/lib/prettyprint/big/src/standard-prettyprint-mill-g.pkg:  Changed pp.ind and pp.exd to have identical semantics to pp.txt except for respectively setting INDENT and EXDENT where pp.txt sets NODENT. This gives much cleaner, more orthogonal semantics and somewhat more compact notation in practice.