Add new files to `shell/common.d`

A small bug was fixed with the `dugigs` and `dumegs` functions.

Added `shell/common.d/git.sh` which provides aliases
`update-submodules`, `glog`, `glog2`, and `glogp` aliases.

Added `shell/common.d/ip.sh` which provides the `ip-public` alias and
`ip-local` function.

Added `shell/common.d/python.sh` which provides functions `activate`,
`makeenv` and `try-it`. Also adds aliases `Deactivate` and `aipy` while
also disabling virtual environments from modifying the shell prompt.