Corrected BCECriterion test

Changed test so that 
a) both input and target have entries lying between 0 and 1
b) both input and target have entries at least 0.01 away from 0 / 1. This is needed to make this test stable - it otherwise fails frequently depending on random initialisation (the numerical approximation of the gradient of log(x) and log(1-x) diverges from the actual values near x=0 and x=1)
MixtureTable:updateOutput
MixtureTable:updateGradInput
Merge pull request #34 from GeorgOstrovski/patch-2

Corrected BCECriterion test
MixtureTable unit tests
MixtureTable:updateOutput (expertInput is a Tensor)
MixtureTable:updateOutput (expertGradInput is a Tensor)
MixtureTable unit tests  (expertInput is a Tensor)
MixtureTable doc
MixtureTable example2 + bug fix
MixtureTable works for 3D tensors (unit tested)
MixtureTable works with 1D inputs (unit tested)
MixtureTable doc++
MixtureTable type-cast unit tests
added FlattenTable module, a unit test and a element in the documentation.

fixed bad formatting in table.md
preparing interface for CUDA
nn.View is mislabeled in the doc.
Merge pull request #36 from jonathantompson/doc_fix

nn.View is mislabeled in the doc.
initial commit for recursive ConcatTable
ConcatTable recursive table unit tested