tools: delete legacy nfdc and nfd-status invocations

The following legacy nfdc sub-commands are deleted:
- register
- unregister
- create
- destroy
- set-strategy
- unset-strategy
- add-nexthop
- remove nexthop

nfd-status no longer accepts command line arguments.

refs #4198

Change-Id: I3ec61fd24c09599c87f07bd92d8f0b5f4e7c70de
diff --git a/docs/manpages/nfdc-status.rst b/docs/manpages/nfdc-status.rst
index c5bdede..cfbdec4 100644
--- a/docs/manpages/nfdc-status.rst
+++ b/docs/manpages/nfdc-status.rst
@@ -11,7 +11,7 @@
 The **nfdc status show** command shows general status of NFD, including its version,
 uptime, data structure counters, and global packet counters.
 
-The **nfdc status report** command generates a comprehensive report of NFD status, including:
+The **nfdc status report** command prints a comprehensive report of NFD status, including:
 
 - general status (individually available from **nfdc status show**)
 - list of channels (individually available from **nfdc channel list**)