Speed up (a) file rename history to minimize file reads; (b) file.isCopy(int) to read metadata for few revisions at once (use pattern assumes earlier revisions are likely to be queried, too); (c) HgIgnore.isIgnored by caching matched initial fragments (to substitute more expensive Matcher.matches with cheaper HashMap.contains)

[section1]
# comment
key1=value 1
key2=value 2
key3=value 3#comment

%include ./included.rc

[section3]
key1=value 1-3

[section1]
key4=value 4
%unset key1