Merge branch 'stable-2.6'
* stable-2.6:
Ignore mergeable bit in ApprovalTable for merged changes
Disallow voting for patch sets other than the current one
ChangeJson: Extract a method for checking ListChangesOptions
Only flatten approvals on submit for the current patch set
Small cleanup in PerformCreateProject
add null check to patchset object while creating descendent changes.
Correct bad name of Access Database capability in error message
Switch to W3C's recommended doctype link for HTML 4.01 Strict
Reflect layout of plain gerrit page on LDAP login page
Use site CSS, header, and footer for LDAP login page
Fix validation errors on LDAP login page
