More hints

[winstliu]

• Lab 5
  • Add hint about rotations
• Lab 6
  • Add hint about duplicate words
  • Remove hint about storing the grid -- getWordInGrid already uses a 500x500 array
• Lab 9
  • Add hint about keeping it simple
  • Add hint about inserting at head
  • Add hint about deleting
• Lab 11
  • Move "getting the itinerary correct" to hints
  • Add hint about sorted permutations

More coming...hoping to knock out all of #93 in this PR

• Lab 8
• Prelab 9 (Collatz, recursion)?
• Prelab 11 (topological -- don't know where to put the hints section yet)

Closes #95
Closes #111

[winstliu]

@aaronbloomfield where would you like the Lab 11 hints to go? I'm not sure where to put them because of the ICPC format.

[winstliu]

This branch has no conflicts with the base branch

Wow I'm surprised. Might still be a good idea though to make sure that the hints are still relevant for the changed labs!

Anyway, perfect is the enemy of good, so might as well get some changes in rather than none.