Inspiration: Apollo 13 -> Allow engineers to repair a broken item by scavenging a similar other broken item instead of using a repair/parts kit (and other repair grit suggestions)

[darthgently]

• For example, if one has two broken solar panels, an engineer of appropriate level should be able to scavenge one to fix the the other as if the other were a parts kit.  The trade off could be that now the other one would require 2 parts kits to get it fully working or something like that (example: Apollo 13 crew). 
• The higher the level of the engineer, the broader the definition of "similar equipment" becomes.  For example, a hypothetical 42 star engineer should be able to repair about anything by scavenging almost anything (for example, see Scotty or Jordy in Star Trek).  See my upcoming post about removing, or at least extending, level limits on Kerbals, and making each type more valuable later in the game.
• The more trivial the scavenged equipment, the more you will need of them to scavenge for a repair; like maybe it would take 1 million scavenged struts to repair a nuclear reactor.  Of course any working equipment scavenged would become broken.  Perhaps tech level, monetary value, and mass of repaired and scavenged equipment could be factored into how much of each would be needed.  And of course the level and number of engineers and perhaps scientists present (think about it)