gitignore: ignore logs/ and terrain/ in all vehicles

We can start sitl in any directoy, which may end up creating these
directories. Ignore them everywhere then.

.gitignore

@@ -31,6 +31,8 @@
 .vagrant
 .tags
 .tags_sorted_by_file
+logs/
+terrain/
 /.lock-waf*
 /.waf*
 /tmp/*
@@ -41,20 +43,15 @@
 /Tools/autotest/jsb_sim/fgout.xml
 /Tools/autotest/jsb_sim/rascal_test.xml
 ArduCopter/Debug/
-ArduCopter/logs/
-ArduCopter/terrain/*.DAT
 ArduCopter/test.ArduCopter/
 ArduCopter/test/*
 ArduCopter/fence.txt
 ArduCopter/ral.txt
 ArduCopter/way.txt
-ArduPlane/logs/
 ArduPlane/test/*
-ArduPlane/terrain/*.DAT
 ArduPlane/test.ArduPlane/
 ArduPlane/way.txt
 APMrover2/way.txt
-APMrover2/logs/
 APMrover2/test.APMrover2/
 mk/PX4/ROMFS/default.parm
 autotest.lck