Could optimize SUB-OUTPUT-INTEGER and DIGIT-TO-CHAR if needed, but I'm
assuming printing of fixnums and bignums is not limited by the
conversion of each digit to a character.

 * src/code/print.lisp:
   * Print integers in lowercase if *print-case* is :downcase
   * Update a docstring.

 * src/i18n/locale/cmucl.pot:
   * Update

 * src/general-info/release-20f.txt:
   * New file with updated info.

implementation details of DISASSEM:DISASSEMBLE.

 code/exports.lisp::
 * Update packages so CL:DISASSEMBLE is not DISASSEM:DISASSEMBLE.

 code/misc.lisp::
 * Define CL:DISASSEMBLE.

 compiler/fndb.lisp::
 * Update defknow for disassemble.

 compiler/disassem.lisp::
 * Print of source codes uses standard I/O syntax instead of
   inheriting from the environment.
 * Add new keyword arguments to DISASSEM:DISASSEMBLE for the base,
   case, and radix.  These default to 16, :downcase, and
   *print-radix*, respectively.  This means disassembly now prints out
   all numbers in base 16 and is in lowercase.
 * When printing a note for an assembler routine, we don't need to
   print the (hex) address if *print-base* is 16.

 compiler/x86/insts.lisp::
 * Fix some issues when in print-mem-access.
   * Sometimes the absolute value of the value was printed instead of
     the value (displaying the wrong value).
   * Print out the value as an unsigned in some cases instead of
     signed value.
 * Fix print-label to print addresses as unsigned integers.  This
   fixes the issue where things like call #x-4xxxxxxx were printed.

 i18n/locale/cmucl.pot::
 * Update because of new or changed docstrings.

format from the file contents ala emacs.

Check if "" (and "/") is in the list of directories and signal an
error so that we use the #P(...) syntax to print out the pathname
readably.

Update the pot and po files accordingly.

Catch the case of " " and signal an error so that we can print such
pathnames using the #P(...) syntax.  Also catch the case where the
directory includes an explicit directory separator, "/", which would
not be printed readably either.

Update the pot file too.

This change requires a cross-compile.  Use boot-2011-04-01-cross.lisp
as the cross-compile script.

bootfiles/20b/boot-2011-04-01-cross.lisp:
o New cross-compile bootstrap file

lisp/lisp.c:
o Recognize -unidata option and setup *UNIDATA-PATH* appropriately.

code/commandline.lisp:
o Add defswitch for unidata so we don't get complaints about unknown
  switch.

code/unidata.lisp:
o Rename +UNIDATA-PATH+ to *UNIDATA-PATH*, since it's not a constant
  anymore.
o Update code to use new name.

code/print.lisp:
o Update code to use *UNIDATA-PATH*

compiler/sparc/parms.lisp:
o Add *UNIDATA-PATH* to list of static symbols.
o Add back in spare-9 and spare-8 static symbols since we need to do a
  cross-compile for this change anyway.

compiler/x86/parms.lisp:
o Add *UNIDATA-PATH* to list of static symbols.
o Reorder the static symbols in a more logical arrangment so that the
  spare symbols are at the end.

i18n/local/cmucl.pot:
o Update