Catch illegal boolean values in hgrc nicely.
With hg 0.9.3 the section and parameter name wasn't printed,
with hg 0.9.4 there was a traceback for ValueError.
uisetup called
ui.parentui isnot None
reposetup called for a
ui == repo.ui
Foo
uisetup called
ui.parentui is None
reposetup called for a
ui == repo.ui
reposetup called for b
ui == repo.ui
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
uisetup called
ui.parentui is None
Bar
% module/__init__.py-style
uisetup called
ui.parentui isnot None
reposetup called for a
ui == repo.ui
Foo