Add BigGridSizeTest test case

Hello Phil,

I have problems when using the *ThreadConfig* interface with a big gridsize.
I think there is something wrong with the GPU memory allocation.

Please have a look at test case *BigGridSizeTest*.

```
$ ant clean && ant && ./pack-rootbeer
$ java -Xmx6g -jar Rootbeer.jar -runtest org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.BigGridSizeTest
caching package names for: /home/martin/workspace/rootbeer2/Rootbeer.jar
caching package names for: /usr/local/java/jdk1.6.0_45/jre/lib/rt.jar
remapping class: java.util.concurrent.atomic.AtomicLong
remapping class: org.trifort.rootbeer.testcases.rootbeertest.remaptest.CallsPrivateMethod
building class hierarchy...
caching virtual methods...
finding entry points...
loading follows strings...
loading to_signatures strings...
entry point: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>
loading forward string call graph for: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>...
remapping: org/trifort/rootbeer/remap/GpuAtomicLong to java/util/concurrent/atomic/AtomicLong
loading reverse string call graph for: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>...
remapping: org/trifort/rootbeer/remap/DoesntCallPrivateMethod to org/trifort/rootbeer/testcases/rootbeertest/remaptest/CallsPrivateMethod
entry point: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>
loading forward string call graph for: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>...
loading reverse string call graph for: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>...
entry point: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>
loading forward string call graph for: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>...
loading reverse string call graph for: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>...
building array types...
numbering types...
loading scene...
finding hierarchy classes reachable from dfs walk...
creating empty classes according to type number...
filling in outer classes...
collecting fields for classes and adding to declaring class...
adding empty methods...
adding method bodies...
Total loaded classes: 1522
Total loaded methods: 4790
getEntryPoints: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>
running transform2 on: <org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.EmptyKernel: void gpuMethod()>...
compiling CUDA code for 32bit and 64bit...
generating serialization bytecode...
added interface CompiledKernel
writing classes out...
Packing up to: output.jar
[TEST 1/1] org.trifort.rootbeer.testcases.rootbeertest.kerneltemplate.BigGridSizeTest@14502a05
  0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
 16: ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 
 32: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
 48: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
 64: 00 00 00 00 00 0e 00 00 20 00 00 00 00 00 00 00 
 80: ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 
 96: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
112: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
128: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
144: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
176: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
192: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
208: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
224: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
240: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
org.trifort.rootbeer.runtime.CudaErrorException: ERROR STATUS:1 : Error in cuMemAlloc: gpu_handles_mem
	at org.trifort.rootbeer.runtime.CUDAContext.cudaRun(Native Method)
	at org.trifort.rootbeer.runtime.CUDAContext.run(CUDAContext.java:411)
	at java.lang.Thread.run(Thread.java:662)
  FAILED
  Exception thrown at index: 0
```

Thanks!

Martin