Fix comments.
Merge pull request #400 from yunosh/fix-sharingsupport-comments

Fix comments.
Depending on the upcoming vobject 3.2
Fixed a potential security issue.
Removed google code upload from build script.
Added php 5.6 and hhvm to travis tests.
Merge branch '1.7' into 1.8

Conflicts:
	ChangeLog
	lib/Sabre/HTTP/Version.php
Merge branch '1.8'

Conflicts:
	.travis.yml
	ChangeLog
	build.xml
	lib/Sabre/DAV/Client.php
	lib/Sabre/HTTP/Version.php
Duplicated line in changelog.
5.6 is no longer allowed to fail.
Fix for #407.
Merge branch '1.7' into 1.8

Conflicts:
	ChangeLog
	lib/Sabre/DAV/Version.php
	lib/Sabre/HTTP/Version.php
Bumped versions
Merge branch '1.8'

Conflicts:
	ChangeLog
	lib/Sabre/DAV/Version.php
	lib/Sabre/HTTP/Response.php
	lib/Sabre/HTTP/Version.php
1.8.8 -> 1.8.9.
Allowing easier overriding of the addressbook home.
XXE security issue.

Issue #414.
Merge branch '1.7' into 1.8

Conflicts:
	ChangeLog
1.8.9 release.
Missing note about sabre/vobject.