* configure.ac (GUILE_PKG): Add 2.0.
* gash/textual-ports.scm: New file.
* Makefile.am: Add it.
* gash/lexer.scm, gash/parser.scm, gash/shell.scm: Use it in place of
'(ice-9 textual-ports)'.
* tests/unit/shell.scm: Use it in place of '(ice-9 textual-ports)';
replace '(ice-9 textual-ports)' with '(rnrs io ports)' in sub-scripts;
and add a shim for 'setvbuf'.
Timothy Sample