* module/ice-9/pretty-print.scm (generic-write)[wr]: Handle read macros
that appear in the middle of a list.
* test-suite/tests/print.test (prints?): New macro.
("pretty-print"): New test prefix.
* module/ice-9/pretty-print.scm (truncated-print): Set
`%default-port-encoding' to the encoding of PORT. Choose either
U+2026 or "..." depending on PORT's encoding.
* test-suite/tests/print.test ("truncated-print")[tprint]: New ENCODING
argument. Update existing tests accordingly. Add UTF-8 tests.
* doc/ref/misc-modules.texi (Pretty Printing): Mention the possible use
of U+2026.