ensuring build script still works on linux
Changing Check into an internal class, adding interfaces IAccountable, IAttribute, IBits. Adding and testing MarkAllBits and MarkNoBits. Adding initial placeholder for porting guidance.
Merge branch 'pcl' of https://github.com/michaelherndon/lucene.net into pcl
starting work on the sorter class. Added the BaseSorterTestCase, Random extensions.
ported InplaceMergeSorter and ArrayInPlaceMergerSorter with tests.  Though setting Stable to true fails because there is a mismatch with ordinal positions which may need to be resolved.
fixed the MatchNoBits tested. Put in temp stop gap measures for the TestInPlaceMergeSorter.
adding clarity to BaseSorterTestCase.cs