test-fileset: test remaining predicates - exec - symlink - size - resolved / unresolved - subrepo

fileset: do not traceback on invalid grep pattern

fileset: matchctx.existing() must consider ignored files When running: $ hg debugfileset 'binary() and ignored()' getfileset() was correctly retrieving ignored files but matchctx.existing() was not taking them in account. Just add them along with unknown files.