Make use of fetch_multi also for targets.

Should partily fix #53, though not yet optimal (cause parser still stays same)

It should be better, then previous one.
While using it, I found that the datastore was called twice when using wildcards. Once within findPaths(), then within evaluateTokensWithTimeSeries().

The issue is : when your timeSeriesList is the result of wildcards expansion, the result of fetchDataMulti is an array of individual TimeSeries object each with an expanded name (without wildcards).
Thus, it will not be possible to match on the name, you will have something like : 
ts.name : stats.counters.srv1
tokens.pathExpression = stats.counters.*