New testsuite

Checking in some tests. 

 * Current coverage [here](http://web.mit.edu/greghale/Public/snap-hpc/)

* Coverage before [here](web.mit.edu/greghale/Public/snap-hpc-before/)

I've still got a bunch of work to do, but thought I might check in now, mainly to provide the test that hits [this](https://github.com/snapframework/snap-core/issues/200) issue about hanging and memory leak on readRequestBody.

Running test suite works best after the sequence:
```bash
cabal clean
cabal sandbox init
cabal sandbox add-sources [all the dependencies]
cabal configure --enable-tests --enable-library-coverage
cabal build
cabal install --enable-tests
./runTestsAndCoverage.sh
```

After changing test code (or anything in the EXCLUDES list of runTestsAndCoverage.sh), it's enough to just
```bash
cabal build
./runTestsAndCoverage
```

But changing any ```src``` file means doing everything from ```cabal clean``` onward again.