compare modified time when running source commands with last compiled binary

[progrium]

When you run a command that is a source directory, Wanix builds the program and caches it in /sys/bin. If it exists there it will run that binary next time. However, if you make changes to the source, it should recompile next time you run it. Currently it will just use the existing binary. We can do this by checking the creation time of the binary against the modified time of the source files, similar to make.