Adds new JavaScript function "js_download"

"js_download" is a JavaScript function used to download data (text
or binary) from the web server.
Add safari webarchive uxss to framework as an aux module.
Merge #1767, @jvennix-r7's .webarchive UXSS

For disclosure details, see:

https://community.rapid7.com/community/metasploit/blog/2013/04/18/abusing-safaris-webarchive-file-format
Added opt delay to file_dropper
Changes made according to feedback from Juan and James
Make sure xor encoders work with odd padding
Add bypass for click2play
Build the jnlp uri when resource is available
Fix @jlee-r7's feedback
Corrects documentation.  Thanks Meatballs1
Fixes P/P/R for target 0 (BadBlue 2.72b)

Target 1, which covers 2.72b, uses an invalid P/P/R from some unknown
DLL, and appears to be broken.  Because 2.72b actually uses the same
ext.dll as BadBlue EE 2.7 (and that target 0 actually also works
against 2.72b), we might as well just use the same P/P/R again.

[FixRM #7875]
Land #1763, @wchen-r7's modification to add js_ajax_download
Let's word this a little differently
Added opt delay to file_dropper
Let's word this a little differently
Landing #1768 - Adds a delay to file_dropper

[Closes #1768]
Merge branch 'master' of github.com:rapid7/metasploit-framework into upstream-master
Let's word this a little differently
Landing #1768 - Adds a delay option for file_dropper.rb

[Closes #1768]
Land #1771, @wchen-r7's fix for ppr address on badblue_passthru