hush: heredoc support, based on patch by Mike Frysinger (vapier AT gentoo.org)

some TODOs are to be attacked later

function                                             old     new   delta
parse_stream                                        1461    1866    +405
parse_redirect                                         -     265    +265
setup_heredoc                                          -     116    +116
setup_redirects                                      151     196     +45
builtin_exit                                          49      47      -2
redirect_opt_num                                      61      55      -6
setup_redirect                                       212       -    -212
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 2/2 up/down: 831/-220)          Total: 611 bytes

shell/hush_test/hush-misc/exec.tests

@@ -1,30 +1,30 @@
 # make sure we have a way of checking these things
-[ ! -e /dev/fd ] && exit 1
+cd /proc/$$/fd || cd /dev/fd || exit 1
 
-[ -e /dev/fd/44 ] && exit 1
+[ -e 44 ] && exit 1
 exec 44>/dev/null
-[ -e /dev/fd/44 ] || exit 1
+[ -e 44 ] || exit 1
 echo pass fd out open
 
-[ -e /dev/fd/55 ] && exit 1
+[ -e 55 ] && exit 1
 exec 55>&44
-[ -e /dev/fd/55 ] || exit 1
+[ -e 55 ] || exit 1
 echo pass fd out dup
 
 exec 44>&-
-[ -e /dev/fd/44 ] && exit 1
+[ -e 44 ] && exit 1
 echo pass fd out close
 
-[ -e /dev/fd/66 ] && exit 1
+[ -e 66 ] && exit 1
 exec 66</dev/null
-[ -e /dev/fd/66 ] || exit 1
+[ -e 66 ] || exit 1
 echo pass fd in open
 
-[ -e /dev/fd/77 ] && exit 1
+[ -e 77 ] && exit 1
 exec 77<&66
-[ -e /dev/fd/77 ] || exit 1
+[ -e 77 ] || exit 1
 echo pass fd in dup
 
 exec 66<&-
-[ -e /dev/fd/66 ] && exit 1
+[ -e 66 ] && exit 1
 echo pass fd in close

shell/hush_test/hush-misc/heredoc1.right

@@ -0,0 +1,5 @@
+qwe
+asd
+123
+456
+Ok

shell/hush_test/hush-misc/heredoc1.tests

@@ -0,0 +1,9 @@
+cat <<000; cat <<www; cat <<eee
+000
+qwe
+asd
+www
+123
+456
+eee
+echo Ok