cppcheck-1.60

new checks:

• dereference iterator and then checking it in condition: 'if (std::isalpha(*i) && i != str.end()) { }'
• calling pure virtual function from constructor/destructor
• assert() condition calls function with side effects

improved checking:

• improved struct member leaks checking
• improved handling of variable initialisation in 'reassignment of variable (first assignment is redundant)' check
• better 'Prefer prefix ++/-- operators' checking for iterators
• handle more complicated patterns in checkIncorrectStringCompare

Lots of false positives and bugs have been fixed.