summary: move mergemod before parents to give access to ms

filemerge: use revset notation for p1/p2 of local/other descriptions

tests: fix for failure of test-convert-p4-filetypes.t Before this patch, test-convert-p4-filetypes.t fails (at least with 2015.2/1366233 version of p4/p4d), because some files below are omitted in expected output for revision 1. - file_tempobj - file_xtempobj These files are: - add-ed at revision 0, and - edit-ed at revision 1 According to perforce command reference below, file type 'tempobj' and 'xtempobj' imply '+S' modifier, which indicates that "Only the head revision is stored". This means that these files should appear only in the most recent revision (= revision 1). https://www.perforce.com/perforce/doc.current/manuals/cmdref/file.types.html BTW, test-convert-p4-filetypes.t with 2015.2/1366233 version of p4/p4d fails similarly also at recent revisions for hgext/convert/p4.py in 2015. Therefore, this patch should be reviewed by perforce guru, to examine whether this failure depends on version (and/or configuration) of p4/p4d or not.