Adapted README to new needs.

tests/README

@@ -1,37 +1,33 b''
 A simple testing framework
 
 To run the tests, do:
 
 cd tests/
 ./run-tests
 
 This finds all scripts in the test directory named test-* and executes
 them. The scripts can be either shell scripts or Python. Each test is
 run in a temporary directory that is removed when the test is complete.
 
 A test-<x> succeeds if the script returns success and its output
 matches test-<x>.out. If the new output doesn't match, it is stored in
 test-<x>.err.
 
 There are some tricky points here that you should be aware of when
 writing tests:
 
 - hg commit and hg up -m want user interaction
 
   for commit use -m "text"
   for hg up -m, set HGMERGE to something noninteractive (like true or merge)
 
 - changeset hashes will change based on user and date which make
   things like hg history output change
 
   use commit -m "test" -u test -d "0 0"
 
 - diff will show the current time
 
-  use hg diff | sed "s/\(\(---\|+++\) [^ \t]*\)[ \t].*/\1/" to strip
+  use hg diff | sed "s/\(\(---\|+++\) [a-zA-Z0-9_/.-]*\).*/\1/" to strip
   dates
 
-- set -x and pipelines don't generate stable output
-
-  turn off set -x or break pipelines into pieces
-