add parameter at($DATE_AT) and mind revisions
remove property rev from xhtml.php
changed variable name $create_time to $modified_time
Merge remote-tracking branch 'remotes/splitbrain/diff_navigation' into revisions
fix function name media_isexternal()
remove empty rev from ml()
rename getProperRevision() to getLastRevisionAt()
make getLastRevisionAt() a method of ChangeLog
add test getlastrevisionat
localize msg
restore old version of pageinfo()
rename function _getProperMediaRevision to _getLastMediaRevisionAt
reduce a bit duplicated code
add test for empty rev in ml() and wl()
Merge remote-tracking branch 'remotes/splitbrain/diff_navigation' into revisions
change behavior only on date_at
Merge branch 'splitbrain/diff_navigation' into revisions
Merge remote-tracking branch 'origin/diff_navigation' into revisions

Conflicts:
	inc/parser/xhtml.php
fix last merge
rename classname
check link existence
fix check link existence, have to call getLastRevisionAt for every link
add missing parameter
Merge remote-tracking branch 'remotes/origin/master' into revisions_local
add config date_at_format
change translation message