MNT : removed ability to back-fill

This seemed clever, but is probably dangerous.
Merge pull request #11 from ericdill/fit

MNT: Removed gui.api and associated files
ENH : two enhancements

Provide more exposed details about the fill rules and the
dimensionality of the data in each column.

Improved validation of the column specs
Merge pull request #12 from tacaswell/col_dim

ENH : improvements to DataMuggler
ENH: Disable plotting based on sliceability of other columns
Revert "MNT: Removed gui.api and associated files"

This reverts commit a7e65fcf1d1b953cdd1fd629c3fbca34f2deb58e.
ENH : make backfill valid again
ENH : make slicable/alignable test smarter
BUG : fix glaring logic errors
Merge pull request #13 from tacaswell/fix_dm

Fix dm
Merge remote-tracking branch 'dill/master'
MNT: Refactored scalar view, model and collection