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.
marked working directory as branch a
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
marked working directory as branch b
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
marked working directory as branch c
c 5:5ca481e59b8c
a 1:dd6b440dd85a
b 4:22df7444f7c1 (inactive)
default 0:19709c5a4e75 (inactive)
-------
c 5:5ca481e59b8c
a 1:dd6b440dd85a