Refactored TH to not use global state for random number generation.

* Style / naming needs work.
* Breaks other layers within torch
Starting point for wrapping the mersenne state in a Lua object.
Miraculously bulds. Very unhappy when you try to run it.
qth runs, can call random methods if you explicitly pass a generator.
Create a generator in the lua torch scope.
Torch tests now pass! Allow all random functions to use the default generator if one isn't supplied when calling the function.
Rename mersenne_state to THGenerator.
Implement method abs() for LongTensor and IntTensor
New test for the abs() method for Int and Long tensors
Add tests for the abs() method for doubles and floats
Merge branch 'master' of github.com:torch/torch7
prevent read/write access from/to an empty tensor to segfault with negative indices
Merge branch 'master' of github.com:torch/torch7
added COPYRIGHT
Remove test that has hard coded line number in the message.
Heinous bug.
multinomial with replacement
Fix build warnings.
Indentation, whitespace, comments.
Reorder arguments to Tensor functions.