Identification of wget command access is incorrect

There's a disconnect between how the module looks for the "wget" command in hook_requirements and how it is configured via the settings page that leads to the module not working.

wget_static_requirements() uses the "which wget" command to identify where the command is. On many servers (and Macs that are using Homebrew) the wget command is not in a default system path, it's installed somewhere else. It does not check the "wget_static_command" variable, so if the settings page had been updated to the correct path it never recognizes this fact. It also sets the "wget_static_cmd_availability" variable to FALSE if the "which wget" command fails, but never allows it to be set to TRUE when the command is set correctly.

The admin page checks the "wget_static_cmd_availability" variable that is set during hook_requirements() and displays a field to edit the command if the variable is FALSE. However, if the form is saved and the correct path is assigned the variable is never updated.