* Changed behavior of `f` to only add flag if there is none
* Changed behavior of `f+` to add flag in any case
* Moved listing subcommands from `f` to `fl`
* Moved listing subcommands from `f.` to `f.l`
* Added subcommand `f.l*` to list all local flags in all functions
* Listing flags at the current offset became `fl.`
* Moved `f=` to `fl=`
* Old `fl` (flag length) now became `fL`
* Removed original `fe` commands
* Old `f?` (check if flag exists) now became `fe`
* Removed `fV` commands
* Removed `fn` commands in favor of `fl` and `asm.flags.real=true`
* Removed `fS` commands (`fSo` and `fSn`)
* `fo` became `fortune` and moved from "flags" to "shell" category
* Removed oldshell handlers of the `z` commands
* Create new category for shell commands in new shell
* Port `env` and `exit`
* Port `ls`, `rm`, `sleep`, `uniq`, `uname` to new shell
* Rename `cname`s for shell commands
* Port `cp`, `cp.` and `echo`
* Port `cd` to newshell
* Add `~` (paths relative to home) handling in `rz_sys_chdir`
* Add `RZ_NONNULL` for `rz_sys_chdir`
* Port `cat`
* Port `mv` and `mkdir` to new shell; Remove old handlers
* Port `pwd`
* Port `sort`
* Remove `cp.` command
* Add `RZ_NONNULL` for arguments of `rz_syscmd_*` functions
* Port `cls` and `clear`
* cd to home when no argument provided
* Fix `mkdir`
* Add alias handling for `cat`
* Fix `mv` command
