entry_processor: improved fake mtime detection.

Report mtime in the future (mtime > now + 24h).
Improve code robustness for corrupted mtimes.

Change-Id: Ideef8167da605695e394be7280a50898ef131ad3
Benchmarking: improved id repartition and avoid faulty getstripe when
benchmarking robinhood DB ingest rate.
FS scan: improved speed statistics.

Change-Id: I5fcda1d5aaa37f2c55105cb150b7bcc3eedac1b7
ListMgr: allow specifying the MySQL DB engine.

Replaced the 'innodb = on/off' parameter with
an 'engine = <enginename>' parameter (defaults to 'InnoDB').

Change-Id: I2b1b74d29cf8286e60b537189606e3ccb7712a86
backup mode: prevent from string overflow when executing custom archive comand.

Archiving a file with name length > 1024 caused an overflow and possibly a SEGFAULT.

Change-Id: I25354be8c3615dfb911a475ab698d0c799088f71
lustre: support of layout swap with an empty layout.

Drop the stripe information in DB when a file is "unstriped".

Change-Id: I03bfca614e5ddba66b17b5dedeb4b5b365922dc7
logs: display non printable characters (eg. from file names) as '?' in the log.

Avoid issues with log parsing tools.

Change-Id: Iafc4409c46c35302dcc4ed9be57386612a7b58a5
FS scan: prevent from dropping entries from DB when opendir fails.

If opendir fails, all entries in the directory where dropped from DB
at the end of a scan, as they hadn't been updated.
For instance, this occurs when the robinhood host is evicted by the MDS,
so the client returns ESHUTDOWN for each opendir.

This patch prevents this by disabling namespace GC at the end of the scan
when such an opendir error is encountered.

Change-Id: I57001381bb6a5f409cc359a039115d9626c8abb2