BUG - (Windows) Shell commands / interactions not compatible

[AljenU]

Most interactions with a shell are not 1-to-1 interchangeable between unix and windows.

Shell interactions happen through functions system, unix and dos, and within AA also aas_shell. They can also happen by having lines of code in the m file starting with a !.

In AA, aas_shell is a dedicated wrapper function around a system call. However, the system function is also used without the aas_shell wrapper in multiple places.

Fixes:

• Preferably, use a matlab provided function instead of doing a shell interaction.
  Example: use mkdir(dirpath) instead of system(sprintf('mkdir %s', dirpath). This also allows for better success checking.
• If there is no matlab provided alternative, have a dedicated aa wrapper function for often-occurring shell interactions.
• Have a dedicated version of the command for use on windows.
• Additionally, make sure all shell interaction goes through aas_shell. And there have an extra input is_pc_safe, default false, to indicate that a command provided to aas_shell has been checked for windows compatibility. If not, throw an error on windows, so as not to execute unchecked code.