CHANGE: inherited meta data is not used when doing a find

CHANGE: getDirectoryMetadata: extract the query that, given a meta name
and pathIDs string, return the values and DirIDs. This is a private
method __getDirMeta.

CHANGE: findDirIDsByMetadata: 
1) use the getPathIDs method to get the current path and its parents
IDs.
2) for the meta dict expanded, use the __getDirMeta method to get the
parents' meta values. If they are there, then delete from the input meta
dict the key as it should not be used for the subsequent query. This
part can also be used to identify conflicting meta data with a clear
message (not done here).
3) use the stripped dict for the DirID query, logic remains untouched. 

This allows queries where one of the parent meta data is used. Until
now, this would result in an empty list (not logical).
FIX: do not return if the meta is not set for the dir nor its parents.

Simply continue to the next meta data.
FIX: add a few methods to the service
FIX: fix typo in FTSRequests
FIX: range for 2 DB items (12 digits)
FIX: don't include in the FTS request info the files that were set
staging
FIX: add caching of files being staged
FIX: do not report files being staged as being in the transfer
FIX: improve usage of sets
FIX: for wrongly formatted Adler cheksum
Merge pull request #1661 from phicharp/FixFTSforStaging-2

[v6r9] Fix fts for staging 2
v6r9p18
Merge pull request #1653 from sposs/FCFindFix

[v6r9] CHANGE: inherited meta data is not used when doing a find
v6r9p19
Some beautification
FIX: DirectoryMetadata - take into account metadata of parent
directories when limiting the file by metadata query by a given path
Merge pull request #1662 from atsareg/rel-v6r9

[v6r9] FileCatalog - proper use of path in files look-up by metadata
Fix for the case "No jobs" + comment one os.unlink
strictly beauty
Recording the sourceSE in case of failover transfer request
FIX: keep cache of staging per channel and print information
FIX checksum comparison using compareAdler
FIX: protect against None lfns in getReplicas