Add BFD peer awareness to frr-reload.py and vtysh markfile

[mrpaulmanley]

This PR is a bugfix for #6511.

frr-reload.py is amended to recognize the peer sub-context in the BFD configuration node. Without this change, it erroneously treats everything under BFD as a single context as shown in this snippet from frr-reload.log

['\nbfd',
 '\nbfd\n peer 169.254.1.1',
 '\nbfd\n detect-multiplier 4']

With the included change, the peer is properly handled as a sub-context, and the peer config is handled properly.

['\nbfd',
 '\nbfd\n peer 169.254.1.1',
 '\nbfd\n peer 169.254.1.1\n detect-multiplier 4']

vtysh.c is amended to also recognize the peer sub-context in the BFD configuration node. Without this change, vtysh -m will not mark the exit of a peer and actually writes an end before the subsequent peers are processed. Without the exit in place for the peer, frr-reload.py will not recognize the need to pop up 1 context level. Here is vtysh -m without the change...

bfd
 peer 169.254.1.1
  detect-multiplier 4
 !
end
 peer 169.254.1.3
  detect-multiplier 4
 !
!

here is the output with the included patch.

bfd
 peer 169.254.1.1
  detect-multiplier 4
 !
exit
 peer 169.254.1.3
  detect-multiplier 4
 !
!

[LabN-CI]

💚 Basic BGPD CI results: SUCCESS, 0 tests failed

Results table

_	_
Result	SUCCESS git merge/6708 b727c12
Date	07/09/2020
Start	13:50:34
Finish	14:16:27
Run-Time	25:53
Total	1815
Pass	1815
Fail	0
Valgrind-Errors	0
Valgrind-Loss	0
Details	vncregress-2020-07-09-13:50:34.txt
Log	autoscript-2020-07-09-13:51:35.log.bz2
Memory	493 499 429

For details, please contact louberger

[NetDEF-CI]

Continuous Integration Result: SUCCESSFUL

Congratulations, this patch passed basic tests

Tested-by: NetDEF / OpenSourceRouting.org CI System

CI System Testrun URL: https://ci1.netdef.org/browse/FRR-FRRPULLREQ-13024/

This is a comment from an automated CI system.
For questions and feedback in regards to this CI system, please feel free to email
Martin Winter - mwinter (at) opensourcerouting.org.

Warnings Generated during build:

Debian 10 amd64 build: Successful with additional warnings

Debian Package lintian failed for Debian 10 amd64 build:
(see full package build log at https://ci1.netdef.org/browse/FRR-FRRPULLREQ-13024/artifact/DEB10BUILD/ErrorLog/log_lintian.txt)

W: frr source: pkg-js-tools-test-is-missing
W: frr source: newer-standards-version 4.4.1 (current is 4.3.0)
W: frr source: pkg-js-tools-test-is-missing
W: frr source: newer-standards-version 4.4.1 (current is 4.3.0)
W: frr-pythontools: changelog-file-missing-explicit-entry 6.0-2 -> 7.5-dev-20200709-01-gb727c12aa-0 (missing) -> 7.5-dev-20200709-01-gb727c12aa-0~deb10u1
W: frr-snmp: changelog-file-missing-explicit-entry 6.0-2 -> 7.5-dev-20200709-01-gb727c12aa-0 (missing) -> 7.5-dev-20200709-01-gb727c12aa-0~deb10u1
W: frr-rpki-rtrlib: changelog-file-missing-explicit-entry 6.0-2 -> 7.5-dev-20200709-01-gb727c12aa-0 (missing) -> 7.5-dev-20200709-01-gb727c12aa-0~deb10u1
W: frr: changelog-file-missing-explicit-entry 6.0-2 -> 7.5-dev-20200709-01-gb727c12aa-0 (missing) -> 7.5-dev-20200709-01-gb727c12aa-0~deb10u1
W: frr-doc: changelog-file-missing-explicit-entry 6.0-2 -> 7.5-dev-20200709-01-gb727c12aa-0 (missing) -> 7.5-dev-20200709-01-gb727c12aa-0~deb10u1