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)

syntax:glob
bin
hg4j*.jar
TEST-*.xml
build/
.gradle/