Enable demandimport only in scripts, not in importable modules (issue605) This way other applications can choose if and when they want this feature, because it might be problematic if those applications rely on ImportError.

adding a
adding b
copy .hg/patches to .hg/patches.1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
M b
a
b
merging with queue at: .hg/patches.1
applying rm_a
Now at: rm_a
b
Patch queue now empty