Change the calculation of cyclomatic complexity

[UFOMelkor]

The changes in detail:

• xor has not been covered yet.
• The ternary operator and the coalesce operator has been count both
  as 2. Also the default case of a switch statement has been counted.
  But as the else statement is not counted because it represents the
  default path (and can be elimated), the default case should not be
  counted (corresponds to else) and both the ternary and the coalesce
  operator should be counted as 1, because they can be exchanged by
  if-else / if which would be counted as 1.
  The spaceship operator by contrast is now counted as 2, because it
  would need if-elseif-else to replace it.
• continue does not increase the cyclomatic complexity as its no
  decision. It's the if around the continue which increases the ccn.

I would be very thankfully about any thoughts to this changes.