More sanity checks.
Preparing release 1.0.3.
Now, when you disable a filter (F4 → Esc), it will go back to unfiltered mode
but the current process will remain selected (so you can filter, choose and
then go back to unfiltered mode to see the children of that process).

Inspired by feedback at http://www.reddit.com/r/linux/comments/23wpc7/announcing_htop_103_with_new_features_bugfixes/ch1paos