ed: improve binary listing (#762)

* I created a binary test file with bytes 0 to 255
* When listing the file content with "l" command I noticed a difference compared to BSD and GNU version
* The "$" character should be listed as "\$" because newlines are represented as plain "$"
* I didn't see a difference for any other characters listed; however the other versions break up long lines (this could be implemented later)

%perl -e'for(0..255){print(chr)}' > in.ed
%pi@raspberrypi:~/PerlPowerTools/bin $ echo ',l' | perl ed in.ed 
Newline appended
257
\000\001\002\003\004\005\006\a\b\t$
\v\f\r\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037 !"#\$%&'()*+,-./0123456789:;<=>?@abcdefghijklmnopqrstuvwxyz[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\177\200\201\202\203\204\205\206\207\210\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227\230\231\232\233\234\235\236\237\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256\257\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277\300\301\302\303\304\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326\327\330\331\332\333\334\335\336\337\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377$

bin/ed

@@ -118,6 +118,7 @@ my %ESC = (
     11 => '\v',
     12 => '\f',
     13 => '\r',
+    36 => '\\$',
     92 => '\\\\',
 );