Fixes #2061

PHP will localize floats (eg. a 45.5 becomes 45,5 in a German locale).
Using a string will prevent that. A fix has been applied on the server end,
but it makes sense to always send the correct message.

remove config option

change translation message

remove empty rev from ml()
rename getProperRevision() to getLastRevisionAt()
make getLastRevisionAt() a method of ChangeLog

changed variable name $create_time to $modified_time

http://english.stackexchange.com/questions/117552/why-does-information-not-have-a-plural-form

This adds $INPUT in all places where it was still missing and available.
$INPUT is now also used in places where using $_REQUEST/... was okay in
order to make the code consistent.

This adds $INPUT in all places where it was still missing and available.
$INPUT is now also used in places where using $_REQUEST/... was okay in
order to make the code consistent.