deprecations for 16.07

[martenson]

please comment with what will be deprecated in 16.07

[carlfeberhard]

Nice! Thanks for setting this up

[carlfeberhard]

(Hopefully no one is using these anymore)
The following URLs will be removed and should be considered deprecated:

• <galaxy>\history\as_xml
• <galaxy>\history\list_as_xml

[davebx]

@carlfeberhard They are mentioned in test/base/twilltestcase.py, but I think I rewrote it to not actually use them.

[martenson]

included in #2821