Add TODO

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

TODO

+Some things which are to be done
+--------------------------------
+
+- cgroups should be used instead of explicit task stops by signals
+- dump/restore of network connections
+- dump/restore of IPC
+- on restore the former process name should be restored as well (use prctl with PR_SET_NAME)
+- consider dropping VMA data from Elf contents but to use program header instead
+- (by Pekka Enberg) add a 'make check' or tools/test script that people can run to
+  do a full fork/dump/restore/kill cycle
+- (by Pekka Enberg) convert kernel patches into a proper kernel git tree people can pull
+- cr-restore.c should be significantly refactored
+- 'crtools show' should support showing only a subset of resources dumped such as
+  pipes/vma/ and etc...