small fixes for test-newbranch
- hg tip doesn't use the branch cache; use hg log -r in its place
- commit doesn't use a HG_MERGE environment variable
- change the dates from "0 0" to "1000000 0"
abort: repository a not found!
255
abort: error: Connection refused
255
abort: repository a not found!
255
abort: destination '../a' already exists
255
abort: repository a not found!
255
abort: destination 'q' already exists