Bugfix: don't perform multiple identical installs for an individual install

Bugfix: don't perform multiple identical installs for an individual install

When calling kit_package_individual() with the W-H-O arguments, the 'O' part may end up being called multiple times.
This happens because some packages, like linux.package, define multiple 'H' parts.
For example, the linux.package defines the following:

'W' = runtime 'W' = runtime 'W' = runtime
'H' = kernel  'H' = modules 'H' = firmware
'O' = main    'O' = main    'O' = main

The 'main' would get called 3 times.
This means that "kit install linux" compiles and installs linux 3 times in a row.

The solution is to remember if an existing 'O' has been processed and skipping already processed 'O's.