* do some calculations once in the constructor instead of for every evaluation of the filter
* make ArrayEvalFilter.ConditionStatement and PathTokenFilter static
use an enum for the expression operator
Merge remote-tracking branch 'upstream/master' into performance-improvements

Conflicts:
	json-path/src/main/java/com/jayway/jsonpath/internal/filter/eval/ExpressionEvaluator.java
Merge remote-tracking branch 'upstream/master' into performance-improvements
Merge pull request #21 from jochenberger/performance-improvements

Performance improvements