Merged pull requests #278, #281, #289, #295, #297, #307, #308, #311, #312, #313, #314.

Added per-host read/write exclusivity to worker programs, so command-line programs don't collide with backups or other operations; reportde by @hamster65 (issue #299) Added $Conf{RsyncIncrArgsExtra} (issue #284) Added $Conf{ClientShareName2Path}, which allows mapping of share names/path to real paths on the client (eg, to backup a snapshot that's in a different directory to the share name path) Fixed v3 digest calculation in bin/BackupPC_backupDuplicate and bin/BackupPC_migrateV3toV4; reported by @palmtop (issue #291) Improved handling of BackupPC_nightly running for more than 24 hours: drop next queued run, and provide better log messages; reported by @guestisp (issue #303) Improved error checking on $Conf{BackupPCNightlyPeriod}, and update $Info->{NightlyPhase} if it's larger than $Conf{BackupPCNightlyPeriod}; reported by @guestisp (issue #304) Fixed warnings in bin/BackupPC, submitted by @moisseev (#278) Avoid rrd updates using the same time stamp, submitted by @moisseev (#311, issue #305) Removed unused counting of renamed files, submitted by @moisseev (#281) Make tar xfer output parsing compatible with FreeBSD tar, submitted by @haarp (#289) Fix daemon stdin open to read mode, submitted by @moisseev (#308) Hosts config editor table layout CGI fix, submitted by @steven-de-wit (#297) Fixes to French translation, submitted by @pjoubert- (#295) Fixes to Italian translation, submitted by @guestisp (#314) Updated comments for Apache 2.4 config in httpd/src/BackupPC.conf, submitted by @NotAProfessionalDeveloper (#307) Documentation update for SCGI prerequisite, submitted by @guestisp (#312) Documentation update for nginx config, submitted by @guestisp (#313)