Cleanup getFirstExpr/getNextExpr and extend virtual methods to cover While/For loops
Bug fix: rename isDoWhileLoop() to isDoWhileStmt()
Introduce the standard isFoo/toFoo functions for While/For loops
Update isSingleLoopIterator to detect For/While loops without reference to blockInfo
Convert uses of blockInfo for While Loops
Fix up virtual method override name mismatch
Update .good to match more detailed compiler error message
Remove dead code; BlockStmt handler superceded by For/While loop specific code
Merge pull request #926 from noakesmichael/nextExpr-2

Continue to separate While stmts from BlockStmt.

a) Extend While/For stmts with overrides for getNextExpr
b) Introduce isFoo/toFoo functions for While/For
c) Update iterators.cpp to avoid calling blockInfoGet() on a while stmt
d) Other minor fixes

Compiled: STD clang/darwin, STD gcc/linux64, LLVM gcc/linux64
Tested: paratest --verify
Review: None