Fix obs.mat feature of fitcn

[ShaiberAlon]

1. Had to change cbind/rbind -> cbind2/rbind2
2. trim the solution after optimization to remove the rows that were added due to obs.mat
3. unrelated to fitcn: added `%+%` = gUtils::`%+%` to apps.R because otherwise sometimes (depending on library include order) the ggplot %+% is used instead of the gUtils.
4. only setting 'grl.labelfield'to "name" if it was not supplied already as a metadata field

cbind2

I honestly don't understand why cbind doesn't work, but it doens't. cbind is supposed to recursively call cbind2, but it doesn't seem to do so. This is quite annoying because cbind2 only works on two matrixes so we need to explicitly call it recursively each time on a pair of matrixes.