check-process.rb has too many options and is too hard to use

[majormoses]

Basically it's great to have something that can do pretty much anything but with that comes extra complexity of understanding how to use it. I think there are a few things we can do:

1. Simplify the code, it is needlessly complex
2. Abstract some of the logic to libraries to make it easier to work with
3. Make more options have no defaults and require specifying them, its impossible to have something with that many options and have sane defaults for everything.
4. Reduce the scope of this check by splitting into different checks.
5. Have better option names (one of the 2 hardest things in CS)
6. Have better option descriptions
7. Put in custom logic to try to trap situations that we see users commonly have options that do not make sense together.

This is motivated by several issues that I have come across as a maintainer and after much investigation it ended in basically not having defaults the user expects:

• check-process.rb filtering behavior does not work as expected #45
• Added -R to check-process.rb for RSS checks #46
• check-process.rb: wrong behaviour if desired process count = 0 #22