Squashed 'nomadic_recording_lib/' changes from 239e191..88c0a9f

88c0a9f new script to simplify removal of ssh hosts whose host keys change periodically
4b8c2b2 bug fixes
e444acb added 'own_callbacks' to fire before others (same functionality as 'Properties')
9abcd90 integrated changes from d23c57d into BaseObject
d23c57d added sorting and ZeroCenteredIndex to ChildGroups
734df7a added a dict-like object that calculates indecies of its items centered around 0.  'ZeroCenteredGroup' seemed like a decent name
39adbea subtree remote fetch raising exceptions. temporarily removed
bd68f2d fixed parsing logic and some issues related to deleted remotes
a06ac04 updated project file
64eac84 added sorted iteration methods to ChildGroups
8418f9f new script to add remotes for subtrees in a repo

git-subtree-dir: nomadic_recording_lib
git-subtree-split: 88c0a9ff1063fc3501261482a7ec9638e0701541
Merge commit '6ced1c4fe7973536e1930217046ace39585b7a69'