Add logical.commands file
Add stubs for logical commands
Implement ws_builtin_cmd_lnot()
Add implementation for ws_builtin_cmd_land()
Add implementation for ws_builtin_cmd_lnand()
Add implementation for ws_builtin_cmd_lor()
Add implementation for ws_builtin_cmd_lnor()
Add implementation for ws_builtin_cmd_lxor()
Merge pull request #274 from matthiasbeyer/add-logical_commands

Logical commands