[snmp/agent] Added some description and the behaviour attribute
[snmp/agent] Fixed snmpa_mib_data behaviour and related

Finalized snmpa_mib_data behaviour. Updated mib-server and
tttn module accordingly. Also assigned proper version, updated
app and appup files.
[snmp] Added doc/index.html file to git ignore
[snmp/agent] Updated documentation and release notes
[snmp/agent] Fixed some test cases
Merge branch 'hb/stdlib/erl_pp_options/OTP-11100' into maint

* hb/stdlib/erl_pp_options/OTP-11100:
  [stdlib] Fix pretty printing of invalid forms
Merge branch 'maint'

* maint:
  [stdlib] Fix pretty printing of invalid forms
Merge branch 'nm/mnesia_idx_insert_speedup/OTP-11103' into maint

* nm/mnesia_idx_insert_speedup/OTP-11103:
  Fix missing case clause for ordered_set tables
  Optimize index creation for Mnesia set tables
Merge branch 'maint'
Introduce a better id allocation algorithm for PTabs
[common_test] Add new option 'no_prompt_check' to ct_telnet:expect/3.

If this option is used, ct_telnet will not search for a prompt before
attempting to match the given pattern. This is useful if, for
instance, the Pattern itself matches the prompt or if the telnet
session starts interactive programs which do not display the normal
prompt.
[common_test] Refactor ct_telnet_SUITE.erl
Merge branch 'siri/cuddle-with-tests' into maint

* siri/cuddle-with-tests:
  Fix gen_server_SUITE:call_with_huge_message_queue
  Fix zip_SUITE:borderline test
[snmp] Added rules to git-ignore to not see patch apply result files
[snmp/agent] Add comment to TTLN file instead of deleting it
Merge branch 'maint'
Fix recognition of 5014 (INVALID_AVP_LENGTH) errors

Invalid lengths come in two flavours: ones that correctly point at the
end of an AVP's payload but don't agree with its type, and ones that
point elsewhere. The former are relatively harmless but the latter leave
no way to recover AVP boundaries, which typically results in failure to
decode subsequent AVP's in the message in question.

In the case that AVP Length points past the end of the message, diameter
incorrectly regarded the error as 5009, INVALID_AVP_BITS: not right
since the error has nothing to do with AVP Flags. Ditto if the length
was less than 8, a minimal header length. Only in the remaining case was
the detected error 5014, INVALID_AVP_LENGTH. However, in this case it
slavishly followed RFC 3588 in suggesting the undecodable AVP as
Failed-AVP, thereby passing the woeful payload back to the sender to
have equal difficulty decoding. Now follow RFC 6733 and suggest an AVP
with a zero-filled payload.
Add spec to diameter_gen
Add spec to diameter_codec
Adapt Failed-AVP setting to RFC 6733

When setting these from an #diameter_packet.errors list, select one
Result-Code or {Result-Code, Failed-AVP}, instead of accumulating all
AVP's from the 2-tuples in the list. This is more in keeping with RFC
6733:

  7.5.  Failed-AVP AVP

     The Failed-AVP AVP (AVP Code 279) is of type Grouped and provides
     debugging information in cases where a request is rejected or not
     fully processed due to erroneous information in a specific AVP.  The
     value of the Result-Code AVP will provide information on the reason
     for the Failed-AVP AVP.  A Diameter answer message SHOULD contain an
     instance of the Failed-AVP AVP that corresponds to the error
     indicated by the Result-Code AVP.  For practical purposes, this
     Failed-AVP would typically refer to the first AVP processing error
     that a Diameter node encounters.

The text of RFC 3588 was less specific, not including the last two
sentences.

Note that an improper AVP Length will result in both 5014 and 5005 being
detected for the same AVP. Without this commit, Failed-AVP would be
populated with two AVP's for the same error.