Rename j* to j1939\1

Using j*smthng* for j1939-related tools is not very good for 2 reasons:
1. j prefix is not very informative;
2. jcat name is used by journal cat tool from popular sleuthkit toolkit;
2`. jacd sounds very similar to jackd.
2``. Possible future name conflicts for new tools.

Thus I renamed j* to j1939\1 to deal with this issue.

Signed-off-by: Alexander GQ Gerasiov <gq@cs.msu.su>

CMakeLists.txt

@@ -36,10 +36,10 @@ set(PROGRAMS_CANLIB
 )
 
 set(PROGRAMS_J1939
-    jacd
-    jcat
-    jspy
-    jsr
+    j1939acd
+    j1939cat
+    j1939spy
+    j1939sr
     testj1939
 )