unittests shouldn't hardcode relative paths

[umlaeute]

the "json-encode/read-large" unit-tests hardcodes a relative path to [json-encode]:

PuRestJson/unittests/json-encode/read-large.pd

Line 8 in b091c4b

#X obj 143 214 ../../json-encode;

in order to be able to run the unit-tests on an already-installed package, this should be changed to just [json-encode] (and let Pd handle the finding of the "correct" binary).

you might also add some flags to the unittest-scripts to allow for specifying the search-paths