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Remove dead code; BlockStmt handler superceded by For/While loop specific code
Fix trivial coverity warning
Update regressions for today
Merge pull request #922 from noakesmichael/cov-0

Fix trivial coverity warning

I recently touched bb.cpp and this caused Coverity to repeat a complaint about dead-code.
It took me a couple of looks to see the issue.  This is a loop over a std::vector<Expr*> and
the body tests whether the element is a NULL pointer or not; in practice this won't happen
for the vector in question but it must have seemed like a nice check when it was added.

However the macro for_vector() terminates early if it is finds a slot with NULL and so the
check is indeed dead-code.

I am not wholly convinced about this definition of for_vector but I think there may
be code that relies on this behavior.

Compiled: darwin/clang
Test: None; The change is trivial and the code is used to print the contents of BBs
Review: None
Merge pull request #923 from thomasvandoren/triage

Update regressions for today
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