Migrate users of breakLabelGet and continueLabelGet to be LoopStmt rather than BlockStmt
Migrate the loop label API from BlockStmt to LoopStmt
uniquify dygraph csv names

We had a STREAM.graph and stream.graph file. One of which overrode the other.
This makes the filename unique. This isn't a great means of making the name
unique.

I'll come back to it later (I ran into this with my other graph work) and add
a check or a better way to make it unique.  There should also probably be a
check to make sure the graph titles are unique.
Merge pull request #997 from ronawho/uniquify-dygraph-csv-name

uniquify dygraph csv names

We had a STREAM.graph and stream.graph file. One of which overrode the other.
This makes the filename unique. This isn't a great means of making the name
unique.

I'll come back to it later (I ran into this with my other graph work) and add
a check or a better way to make it unique. There should also probably be a
check to make sure the graph titles are unique.
Merge pull request #998 from noakesmichael/label-0

Migrate labels from BlockStmt to LoopStmt

1) Update a few locations that were reading the break/continue label through a BlockStmt*

2) Move the instance variables and methods.

Compiled: STD clang/darwin, STD gcc/linux64, LLVM gcc/linux
Tested: paratest --verify; ignored the BLOCK_UNLOCAL regression
Review: none