adding the following yum commands:
* update-to (just what update expands)
* upgrade-to (just what update expands)
* history (the actual tricky one)
* help (printing the available commands)
* load-transaction (_files)
* load-ts (_files)
* check (just what the man page suggested)
* reinstall (just what erase does - suggest installed packages)
* downgrade (just what erase does - suggest installed packages)
* repolist (just what the man page suggested)
* distribution-synchronization (just what erase does - suggest installed packages)
* distro-sync (just what erase does - suggest installed packages)
A few history commands don't get expanded.
Taken from the man page of yum 3.2.29.
Reindented file.