Formatter: Correctly format stars in `sizeof(int**)` and similar places.

This redoes how '*' and '&' are classified as pointer / reference markers when
followed by ')', '>', or ','.

Previously, determineStarAmpUsage() marked a single '*' and '&' followed by
')', '>', or ',' as pointer or reference marker. Now, all '*'s and '&'s
preceding ')', '>', or ',' are marked as pointer / reference markers. Fixes
PR14884.

Since only the last '*' in 'int ***' was marked as pointer before (the rest
were unary operators, which don't reach spaceRequiredBetween()),
spaceRequiredBetween() now had to be thought about handing multiple '*'s in
sequence.

Before:
  return sizeof(int * *);
  Type **A = static_cast<Type * *>(P);

Now:
  return sizeof(int**);
  Type **A = static_cast<Type **>(P);

While here, also make all methods of AnnotatingParser except parseLine()
private.

Review URL: http://llvm-reviews.chandlerc.com/D384