added metasploit http DoS module

[deepsight]

Adding a module for for CVE-2019-5645, Denial of Service on Metasploit framework HTTP(s) handler.

[jmartin-tech]

Please update the disclosure date to ISO 8601 format as 2019-09-04.

[*] Running msftidy.rb in ./.git/hooks/post-merge mode
--- Checking new and changed module syntax with tools/dev/msftidy.rb ---
modules/auxiliary/dos/http/metasploit_httphandler_dos.rb - [ERROR] Incorrect disclosure date format
modules/auxiliary/dos/http/metasploit_httphandler_dos.rb - [WARNING] Please add a newline at the end of the file

[busterb]

Updated options to take an enum, fixed some other minor things, verified function, and added module docs. Thanks @deepsight and @bcoles for the review.

[busterb]

Release Notes

This add a DoS module targeting a regex parsing weakness in reverse_http and reverse_https payload handlers in Metasploit 5.0.27 and below.

[jirayutza1]

Please update the disclosure date to ISO 8601 format as 2019-09-04.

[*] Running msftidy.rb in ./.git/hooks/post-merge mode
--- Checking new and changed module syntax with tools/dev/msftidy.rb ---
modules/auxiliary/dos/http/metasploit_httphandler_dos.rb - [ERROR] Incorrect disclosure date format
modules/auxiliary/dos/http/metasploit_httphandler_dos.rb - [WARNING] Please add a newline at the end of the file

Please update the disclosure date to ISO 8601 format as 2019-09-04.

[*] Running msftidy.rb in ./.git/hooks/post-merge mode
--- Checking new and changed module syntax with tools/dev/msftidy.rb ---
modules/auxiliary/dos/http/metasploit_httphandler_dos.rb - [ERROR] Incorrect disclosure date format
modules/auxiliary/dos/http/metasploit_httphandler_dos.rb - [WARNING] Please add a newline at the end of the file