fileset: use decorator to mark a function as fileset predicate Using decorator can localize changes for adding (or removing) a fileset predicate function in source code. It is also useful to pick predicates up for specific purpose. For example, subsequent patches marks predicates as "call status" or "use existing" via decorator. To avoid (1) redundancy between "predicate name" and (the beginning of) help document, and (2) accidental typo of help document, this patch also makes decorator put predicate declration into the beginning of help.

fileset: treat encoding and eol as the predicate calling _existing Before this patch, predicate function 'encoding' and 'eol' aren't listed up in '_existingcallers', even though they invoke 'existing()'. This causes unexpected failure of these predicate, if there is a (manually) deleted file in the working directory. 8a0513bf030a and 3ce3f2b059a1 seem to overlook putting already existing 'encoding' or newly introduced 'eol' into '_existingcallers'. This patch also changes order of fileset "eol(unix)" output in test, because "existing caller" predicates show "A(dded)" files before "C(lean)" ones.